一种基于分簇的WSN时间同步算法

论文提出了一种基于分簇结构的无线传感器网络时间同步算法.在分簇网络结构中,参考DMTS,仿照TPSN采用在MAC层给控制帧标记时同戳的方式,实现了传感器节点的能量效率,进一步提高了时间同步精度.分析表明.本算法在精度和能耗上都有所改进.     

基于博弈的大规模无线传感器网络分簇算法

合理的分簇方式能够有效延长大规模无线传感器网络(LS-WSN)的寿命,从而降低其部署使用成本。当前很多WSN分簇的研究均假设节点均匀分布,这与实际应用中的大规模WSN有所差距。该文针对节点非均匀分布的大规模WSN,提出了一种分簇算法。该算法在基于蜂窝结构虚拟网格的位置分簇之后,引入博弈理论设计分簇调整流程,使网络达到各簇中节点数尽量均匀的分簇状态。理论分析和仿真结果证明,通过该方法进行分簇,可以有效均衡各个簇中的节点数,从而延长网络有效寿命。     

Adaptive Cross-Layer Routing Protocol for Optimizing Energy Harvesting Time in WSN

Wireless Personal Communications - Trade-off between energy conservation and efficiency is one of the most important issues in designing Wireless Sensor Network (WSN) based applications. Network...     

A Novel Approach to Optimize Power Consumption in Orchard WSN: Efficient Opportunistic Routing

Wireless Personal Communications - In orchard wireless sensor networks (WSN) application, the network link quality is unstable due to the shielding effect caused by the growth of branches and...     

一种双基地雷达时间同步的新方法

提出了一种基于对流层散射双向时间比对的双基地雷达时间同步的新方法(TWT3S), 利用对流层散射通信设备进行雷达站间双向时间比对以求取雷达站间精确的时间差。详细推导了TWT3S的计算模型, 对时间间隔测量误差、发射与接收设备时延误差、对流层时延误差、几何距离时延误差进行了讨论, 并给出了TWT3S的理论精度。计算结果表明, 对流层时延误差是最主要的误差来源, 占所有误差的90%以上。TWT3S模型的理论精度为15~21 ns, 比采用微波或光纤直接同步法精度高, 为双基地雷达时间同步提供了新的思路。     

实现双／多基地雷达时间同步的一种新方法

介绍了实现双/多基地雷达时间同步的一种新方法。这种方法从卫星电视信号中提取场同步信号,再以此实现时间同步。通过对伪码调相连续波雷达的初步外场试验,验证了这种方法的可行性。     

铁路时间同步网综合原子时标的研究

铁路时间同步网为铁路各系统提供统一的标准时间量值,其精确、稳定与否对铁路系统安全、高效地运营具有重要影响。根据调研,当前铁路时间同步网的潜在问题有：各时间节点时间溯源参考不一致,且未精确溯源至协调世界时(UTC);仅设置1处的1级时间节点故障时,2,3级时间节点受其影响大、鲁棒性不足;监测手段仅针对单个节点,缺乏整体层面的自动监测方法。针对以上潜在问题,该文提出可精确溯源至UTC的铁路时间同步网综合原子时标(TE)作为网内统一的时间溯源参考的解决方案,通过建立铁路时间同步网仿真模型,研究设计了综合原子时标算法,基于1级、2级时间节点19台母钟设备形成了TE。仿真结果表明,TE与UTC的溯源偏差可优于30 ns,溯源不确定度可优于5 ns;1级时间节点正常运行时,引入TE可提高2级时间节点时间稳定度约40%;1级时间节点故障时,TE仍可持续生成并作为网内统一的时间溯源参考, TE同步架构下的2级时间节点与传统同步架构下的相比,其频率、时间稳定度提高约35%;基于TE可获取任意节点间时差,通过分析时差数据,可实现整体层面的所有时间节点、精确时间协议(PTP)链路通断的自动监测。     

大规模水下传感器网络时间同步研究

该文针对大规模水下传感器网络,对信标节点覆盖内的节点,设计了基于静态信标节点的时间同步算法;对信标节点覆盖范围外的节点,设计了动态节点辅助的时间同步算法。减少了节点移动对同步精度的影响。同时,根据水下声速变化规律,设计了水下传感器网络分层时间同步机制,有效克服了已有算法在处理大规模水下传感器网络时间同步问题上的不足。仿真结果表明,该方法的同步效果明显好于现有的算法。     

EERPLS:一个大规模传感器网络中的高能效路由协议

提出了一种适合于大规模无线传感器网络的高能效路由协议EERPLS,其主要思想是:将直线虚拟拓扑与链式簇的思想结合起来在大规模传感器网络中实现能量高效路由.模拟结果显示EERPLS不仅突破了规模的限制,而且有效地均衡了整个网络中的能量消耗,达到了延长网络生存周期的目的.     

A Novel Simple Semi-Empirical Model for the Effective Earth Radius Factor

This paper presents a dual cumulative probability distribution model for predicting the cumulative distribution of the probability that a particular value of the propagation k-factor will be exceeded. The distributions relate to so-called "dry" and "wet" (or "climatic") components. The model is based on meteorological radiosonde data observed over a period of some 11 years and published by other workers. The model is extended by a simple height regression analysis in order to predict the cumulative behavior of the k-factor at different ground level heights in the summer rainfall area of South Africa during different months. Comparisons are made between predicted and observed data. The model may have potential applications in other parts of the world where data on k-factor behavior are scarce     

三网融合背景下的大规模FTTH建设

在信息化发展对带宽需求不断增加以及三网融合的背景下,从PON设备、ODN网络及FTTH施工工艺等方面阐述了大规模FTTH建设中需重点考虑的问题。     

WSN经典路由协议比较

本文首先介绍了WSN路由协议的特殊性、路由协议的分类等,然后针对WSN的几个经典路由协议,从协议的实现过程、协议特点、优缺点、适用领域等方面进行了分析,最后对这些路由协议的节能性、可扩展性、鲁棒性等方面进行了比较,以期为WSN路由协议的选用及进一步研究提供参考。     

A Novel Parallel Scheme for Fast Similarity Search in Large Time Series

The similarity search is one of the fundamental components in time series data mining,e.g.clustering,classification,association rules mining.Many methods have been proposed to measure the similarity between time series,including Euclidean distance,Manhattan distance,and dynamic time warping(DTW).In contrast,DTW has been suggested to allow more robust similarity measure and be able to find the optimal alignment in time series.However,due to its quadratic time and space complexity,DTW is not suitable for large time series datasets.Many improving algorithms have been proposed for DTW search in large databases,such as approximate search or exact indexed search.Unlike the previous modified algorithm,this paper presents a novel parallel scheme for fast similarity search based on DTW,which is called MRDTW(MapRedcuebased DTW).The experimental results show that our approach not only retained the original accuracy as DTW,but also greatly improved the efficiency of similarity measure in large time series.     

A New Approach for Time Synchronization in Wireless Sensor Networks: Pairwise Broadcast Synchronization

This letter proposes an energy-efficient clock synchronization scheme for Wireless Sensor Networks (WSNs) based on a novel time synchronization approach. Within the proposed synchronization approach, a subset of sensor nodes are synchronized by overhearing the timing message exchanges of a pair of sensor nodes. Therefore, a group of sensor nodes can be synchronized without sending any extra messages. This paper brings two main contributions: 1. Development of a novel synchronization approach which can be partially or fully applied for implementation of new synchronization protocols and for improving the performance of existing time synchronization protocols. 2. Design of a time synchronization scheme which significantly reduces the overall network-wide energy consumption without incurring any loss of synchronization accuracy compared to other well-known schemes.     

SZM-LEACH:一种层簇式的WSN安全跨区多跳路由协议

针对经典成簇协议LEACH面临的安全威胁,提出了一种新的安全跨区多跳层簇式路由协议(SZM-LEACH).其核心思想是通过分区自治建立安全簇首表格,并在路由建立过程中通过密钥管理实现安全路径建立.仿真实验表明,改进的路由机制可以有效减少因恶意节点而导致的数据丢失,同时显著增加网络生命周期,降低网络能耗.     

大规模地形实时绘制算法研究

在大规模场景的地形简化中,海量数据的内外存调度算法一直是热点研究问题。提出了一种高效的大规模地形数据调度算法,算法设计了一种有效的地形网格数据的多分辨率存储方法,减少了简化过程中实时数据调度量,同时算法对地形分块与内存分块进行了优化处理,从而提高了大数据量地形数据的实时调度效率。实验结果证明了算法的有效性。     

MOMHR: A Dynamic Multi-hop Routing Protocol for WSN Using Heuristic Based Multi-objective Function

Wireless Personal Communications - Wireless sensor networks (WSNs) are the networks which mainly focuses on the applications and are composed of considerable sensor nodes. The use of energy in a...     

Q-MOHRA: QoS Assured Multi-objective Hybrid Routing Algorithm for Heterogeneous WSN

Quality of Service (QoS) assurance in Wireless Sensor Network (WSN) is a tough task, and it is more exciting due to the scarcity of resources. The requirement of different WSN applications running over has different constraints. In QoS, routing protocol the network has to balance the traffic. This paper presents a novel heuristic routing algorithm known as QoS assured Multi-objective Hybrid Routing Algorithm (Q-MOHRA) for Heterogeneous WSN. Q-MOHRA takes into account the link (energy, hop count, link quality indicator etc.) and path (jitter) metrics for optimal path selection. The performance of Q-MOHRA is evaluated through intensive simulation and equated with Simple Hybrid Routing Protocol (SHRP) and Dynamic Multi-objective Routing Algorithm (DyMORA). The metrics such as average energy consumption, residual energy, packet delivery ratio, jitter, and normalized routing load are used for comparison. The performance of Q-MOHRA has been observed to outclass SHRP and DyMORA. It improves the packet delivery ratio by 24.31% as compared to SHRP and 11.86% as compared to DyMORA. Q-MOHRA outperforms DyMORA in terms of average energy consumption by a factor of 8.27%.     

基于仿人体血管路径WSN故障容错路由算法研究

为提高无线传感器网络(WSN)故障容错性和传输稳定性,实现网络负载均衡,提出了一种仿人体血管路径的WSN故障容错路由算法.通过研究人体血管路径特性,将其引入到WSN故障容错路由设计中,在对网络节点分区域进行等级标定的基础上实行能耗均衡的静态分簇;运用改进的蚁群算法生成节点路径并计算各路径信息素值,以确定传输路径选择概率并建立仿血管拓扑结构路由.理论与仿真结果表明,此算法具有良好的性能.     

基于PSWF的非正弦通信系统同步方法

基于椭圆球面波函数(Prolate Spheroidal Wave Function,PSWF)的非正弦时域正交调制信号的自相关值呈现明显的起伏震荡特性,这给同步检测带来了较大的困难。针对这一问题,提出了一种采用m序列调制基带PSWF脉冲作为同步头的同步提取方法,该同步头具有尖锐的自相关峰,有效解决了同步困难的问题。同时,给出了该同步方法的实现方式,可有效降低同步捕获过程运算量,缩短同步捕获时间,提高同步捕获精度。