无线火灾监控系统在坑、地道式防护工程中的应用研究

针对目前我国坑、地道式防护工程火灾监测系统存在的问题,设计一种无线火灾监控系统,该系统由传感器节点、路由节点、网关节点以及PC机组成。介绍了该探测系统传感器节点和网关节点的硬件设计以及传感器节点、路由节点、网关节点的功能、流程等软件设计。该系统集监测、显示、报警、通信等多功能于一体,可以对目标区域进行远程监控,监测节点体积小,无需布线,移动、安装方便。     

Topology control in the presence of jammers for wireless sensor networks

In this paper, the problem of ensuring packet delivery ratio and high network lifetime in wireless sensor networks in the presence of single or multiple jammers is studied using single‐leader‐multiple‐followers Stackelberg game theory. A topology control scheme is proposed, in which the sink node, which acts as the leader, identifies the set of jamming affected nodes. On the other hand, the sensor nodes, which act as followers, need to decide an optimum transmission power level, while ensuring an optimal set of neighbor nodes covered. A scheme, named TC‐JAM, for ensuring packet delivery ratio, while avoiding jammers and increasing network lifetime in wireless sensor networks, is proposed. In existing literatures, the sensor nodes are envisioned to be equipped with multiple interfaces, while having access for multiple channels. However, in TC‐JAM, the sensor nodes have simple hardware with single interface for communication, ie, the sensor nodes have single channel for communication. Additionally, in the proposed scheme, TC‐JAM, each sensor node has a provision to vary its transmission power according to the chosen strategies. Using TC‐JAM, the energy consumption of the overall network reduces by up to 62%, and the network lifetime increases by 56% to 73%.     

Throughput Evaluation of a Novel Scheme to Mitigate the Congestion over WSNs

In recent years, due to fast development of wireless sensor networks (WSNs), the numbers of nodes are increasing, and their scope of applications is continuously expanding, including environmental monitoring, military and smart home applications. The power supply, memory and computing power of wireless sensor nodes are greatly hampered in WSNs so that the WSNs are classified as a task-oriented framework. This study focused on exploring problems caused by traffic congestion on the WSNs with a large amount of flow, such as packet loss, bandwidth reduction, and waste of energy on the sensor nodes. On the other hand, a cooperative strong node mechanism is presented and named as Cooperative Strong Node Mechanism, in which a threshold is set to determine whether the node traffic is over or not. When the load exceeds, the privilege of corresponding sensor nodes is upgraded so that it can command its child nodes to change the transmission path to distribute the traffic effectively. Furthermore, when the traffic exceeds preset overall network flow, new sensor nodes are added in the network to relieve the traffic. This novel proposed mechanism can not only increase network throughput and effectively prevent the occurrence from congestion problems, but is suitable for a variety of routing protocols.     

Optimizing Lifetime for Continuous Data Aggregation With Precision Guarantees in Wireless Sensor Networks

This paper exploits the tradeoff between data quality and energy consumption to extend the lifetime of wireless sensor networks. To obtain an aggregate form of sensor data with precision guarantees, the precision constraint is partitioned and allocated to individual sensor nodes in a coordinated fashion. Our key idea is to differentiate the precisions of data collected from different sensor nodes to balance their energy consumption. Three factors affecting the lifetime of sensor nodes are identified: 1) the changing pattern of sensor readings; 2) the residual energy of sensor nodes; and 3) the communication cost between the sensor nodes and the base station. We analyze the optimal precision allocation in terms of network lifetime and propose an adaptive scheme that dynamically adjusts the precision constraints at the sensor nodes. The adaptive scheme also takes into consideration the topological relations among sensor nodes and the effect of in-network aggregation. Experimental results using real data traces show that the proposed scheme significantly improves network lifetime compared to existing methods.      

无线传感器网络节点的设计

无线传感器网络是一种以无中心节点的全分布系统。通过随机投放的方式,众多传感器节点被密集部署于监控区域。这些传感器节点集成有传感器、数据处理单元和通信模块,它们通过无线信道相连,自组织地构成网络系统。传感器节点借助于其内置的形式多样的传感器,测量所在周边环境中的相关信号,传感器节点间具有良好的协作能力,通过局部的数据交换来完成全局任务。     

基于冗余节点休眠和分阶段唤醒策略的传感器网络三维覆盖控制方法

该文针对无线传感器网络中节点能量有限且密集布点时存在大量冗余节点的情况,提出了基于冗余节点休眠和分阶段唤醒策略的无线传感器网络3维覆盖控制方法。在3维待监测区域中随机配置大量传感器节点,达到高密度分布,使冗余节点处于休眠状态,等待活跃节点能量耗尽之后,分阶段唤醒休眠节点,直至整个传感器网络中所有节点的能量都耗尽为止。仿真结果表明,该方法提高了传感器网络的网络性能,且对相同的传感器节点数,分阶段唤醒策略优于不分阶段的唤醒策略,先使冗余节点休眠之后再唤醒方法的网络性能高于直接唤醒方法的网络性能。     

On the Detection of Clones in Sensor Networks Using Random Key Predistribution

Random key predistribution security schemes are well suited for use in sensor networks due to their low overhead. However, the security of a network using predistributed keys can be compromised by cloning attacks. In this attack, an adversary breaks into a sensor node, reprograms it, and inserts several copies of the node back into the sensor network. Cloning gives the adversary an easy way to build an army of malicious nodes that can cripple the sensor network. In this paper, we propose an algorithm that a sensor network can use to detect the presence of clones. Keys that are present on the cloned nodes are detected by looking at how often they are used to authenticate nodes in the network. Simulations verify that the proposed method accurately detects the presence of clones in the system and supports their removal. We quantify the extent of false positives and false negatives in the clone detection process.     

建筑物抗震性无线检测系统的设计

介绍了一种基于无线传感器网络技术的建筑物抗震性检测系统.首先,提出了以无线通信震动传感器形成一种可扩展的无线传感器网络的系统结构.然后,介绍在该系统中采用的无线震动传感器节点以及检测基站设备的设计.在本系统中,节点和基站设备所使用的近距离通信标准为802.15.4/ZigBee标准.     

The Impact of Deployment Pattern and Routing Scheme on the Lifetime in Multi-Sink Wireless Sensor Network

Extensive use of sensor and actuator networks in many real-life applications introduced several new performance metrics at the node and network level. Since wireless sensor nodes have significant battery constraints, therefore, energy efficiency, as well as network lifetime, are among the most significant performance metrics to measure the effectiveness of given network architecture. This work investigates the performance of an event-based data delivery model using a multipath routing scheme for a wireless sensor network with multiple sink nodes. This routing algorithm follows a sink initiated route discovery process with the location information of the source nodes already known to the sink nodes. It also considers communication link costs before making decisions for packet forwarding. Carried out simulation compares the network performance of a wireless sensor network with a single sink, dual sink, and multi sink networking approaches. Based on a series of simulation experiments, the lifetime aware multipath routing approach is found appropriate for increasing the lifetime of sensor nodes significantly when compared to other similar routing schemes. However, energy-efficient packet forwarding is a major concern of this work; other network performance metrics like delay, average packet latency, and packet delivery ratio are also taken into the account.

     

On the design of secure user authenticated key management scheme for multigateway‐based wireless sensor networks using ECC

In wireless sensor networks (WSNs), there are many critical applications (for example, healthcare, vehicle tracking, and battlefield), where the online streaming data generated from different sensor nodes need to be analyzed with respect to quick control decisions. However, as the data generated by these sensor nodes usually flow through open channel, so there are higher chances of various types of attacks either on the nodes or on to the data captured by these nodes. In this paper, we aim to design a new elliptic curve cryptography–based user authenticated key agreement protocol in a hierarchical WSN so that a legal user can only access the streaming data from generated from different sensor nodes. The proposed scheme is based upon 3‐factor authentication, as it applies smart card, password, and personal biometrics of a user (for ticket generation). The proposed scheme maintains low computation cost for resource‐constrained sensor nodes, as it uses efficient 1‐way cryptographic hash function and bitwise exclusive‐OR operations for secure key establishment between different sensor nodes. The security analysis using the broadly accepted Burrows‐Abadi‐Needham logic, formal security verification using the popular simulation tool (automated validation of Internet security protocols and applications), and informal security show that the proposed scheme is resilient against several well‐known attacks needed for a user authentication scheme in WSNs. The comparison of security and functionality requirements, communication and computation costs of the proposed scheme, and other related existing user authentication schemes shows the superior performance of the proposed scheme.     

一种新的无线传感器网络传输机制RNTA算法的研究与仿真

针对无线传感器网络体积小与能量受限的特点,该文提出了一种新的传输机制RNTA算法,即将无线传感器网络中的部分冗余节点组成中继树,并利用该树作为网络内信息传输的代理,完成了信息从簇头到基站的传输,达到了节省正常节点和簇头能量的目的。仿真结果表明:该机制可以有效提高网络的生命周期。     

Timing-Based Mobile Sensor Localization in Wireless Sensor and Actor Networks

In this paper, localization problem in wireless sensor and actor networks (WSAN) is addressed. In WSAN, the performance of event detection and tracking highly depends on the exact location information of the events that must be reported along with the event features. Having precise location information of the sensor nodes, actors are able to execute actions more effectively in the region of detected events. In this context, the accurate localization of sensor nodes is essential with respect to the actors. Particularly, the problem becomes much more complicated when the sensor nodes as well as the anchor nodes (actors) are mobile. In order to localize the mobile sensor nodes relative to the actors, a novel Timing-based Mobile Sensor Localization (TMSL) algorithm is introduced. In TMSL, sensor nodes determine their distance from actors by using propagation time and speed of RF signal. In order to determine distance from the actors, actors actively broadcast reference beacons in a pattern of intervals adaptively defined according to the mobility of sensor nodes and the required level of localization accuracy. These reference beacons carry the interval numbers in which they were transmitted. The interval numbers are then used by the sensor nodes to calculate the start time of the beacons locally which is then used to determine the propagation time. TMSL does neither require nor assume any time synchronization among the sensor nodes or with the actors. Performance evaluations clearly show that TMSL is adaptive to velocity of mobile sensor and actor nodes and can be configured according to the required localization accuracy in order to avoid overhead raised due to high velocity.     

Identifying Neighbor and Connectivity of Wireless Sensor Networks with Poisson Point Process

Identifying neighbor and connectivity are the fundamental requirements in wireless sensor networks. The sensor nodes are scattered randomly over the area of interest and their first step is to identify their immediate neighbors, i.e., the nodes with which they have direct wireless communication. On the other hand, connectivity ensures that sensor nodes can communicate with each other in order to aggregate sensing data hop by hop to the base stations (sink nodes). In this paper, we study identifying neighbor and connectivity in the context of wireless sensor networks, using Poisson point process theory.     

分布式无线感知网络节点部署算法研究

在无线感知网络节点部署中,目标区域的覆盖率大小对信号检测的效果具有重要的意义,通过智能优化算法来提高区域覆盖率已成为当前无线感知网络节点部署领域的研究热点之一。为了提高分布式无线感知网络对目标区域内的重点区域的覆盖率和减少冗余感知节点的投放,论文提出了一种分布式无线感知网络节点部署算法。该算法首先通过随机部署满足连通性的少量感知节点后初次工作来定位和估计出重点区域,然后将估计出的重点区域融入到粒子群算法的目标函数和粒子更新方程中实现对感知节点的重新部署,从而更好的优化了重点区域的覆盖率和减少冗余感知节点数量。仿真结果表明,与标准粒子群算法及其他优化算法相比,论文所研究的算法有更高的覆盖率和更低的迭代次数。      

无线传感器网络节点的辅助式定位方法

节点定位是无线传感器网络的一个重要研究内容。针对传感器网络内所有节点物理位置都未知的情况，文中提出一种利用已知的外界参考信号源来对网络内传感器节点进行定位的方法，并建立了基于TDOA、TOA及AOA的定位估计模型。尽管参数测量有误差，但所提出的方法能够提供有效的位置信息及一定的精度，而且基于AOA的定位模型并不增加传感器节点的成本和复杂度。仿真实验结果表明，该方法能对节点进行有效的定位。     

基坑监测系统中传感网的节点部署

基坑监测系统中,需要在各监测点部署传感器节点,系统的监测点围绕基坑工程展开,其监控区域近似圆环。在基站收集监测数据时,离基站越近的区域需要转发的数据越多,节点能量消耗速度也就越快,基站附近的节点将很快消耗完能量,系统随即瘫痪。通过研究圆环形传感网的拓扑特点,得到节点密度公式,使得各区域的总能量与能量消耗速度之比达到平衡。理论分析和仿真实验表明,按照此密度公式部署传感器节点,可显著提高系统生命周期。     

Exploiting edge capability for wireless sensor networking

As considerable progress is being made in wireless sensor networking, it is envisioned that sensor nodes will be on the cubic millimeter scale, posing stringent constraints on the processing, communication, and storage capabilities of sensor nodes. While it is important to continue pursuing novel algorithms and protocols to squeeze the most out of the existing design space (sensor nodes), it is equally important to explore a new design paradigm for future sensor networks to reduce the complexity burden on sensor nodes. We propose to exploit capabilities at the network edge (i.e., an edge-based approach). We overview existing approaches to this end and present a novel edge-based routing protocol, called BeamStar, as a case study. We show that exploiting edge capability provides a new dimension of freedom for wireless sensor networking, and is effective in relieving the processing, communication, and storage requirements of sensor nodes.     

Concentric Distributed Localization Based on the Tripodal Anchor Structure and Grid Scan for Wireless Sensor Networks

Achieving high accuracy with minimum reference nodes, anchor nodes, and computation and communication costs is a goal for the localization in wireless sensor networks. Targeting at this goal, a localization scheme called concentric distributed localization with the tripodal anchor structure and grid scan (CDL-TAGS) requiring two reference nodes and a few anchor nodes is proposed in this paper. Under the precondition that the system has randomly distributed normal sensor nodes, a tripodal anchor structure is first designed. With this structure, the localization process is started from the centroid node and then stretched outward to the farthest normal nodes. Based on the two best reference nodes, a virtual point is generated to serve as the third reference node. In the CDL-TAGS scheme, a grid scan algorithm is employed to estimate the position of a normal node. Finally, we show that the communication overhead and time and space complexities among sensor nodes for CDL-TAGS can be kept at a low level. In addition, CDL-TAGS can achieve better accuracy with minimum anchor nodes as compared to some closely related localization schemes in the literature through simulation results.     

一种无线传感器网络异构分簇模型的簇头调度方案

将无线传感器网络划分成簇会有效利用系统资源,近来提出的基于异构分簇模型的无线传感器网络,是指网络中存在多种不同能力的节点,能力强的节点自动成为簇头,这种网络避免了复杂的簇头选举过程并有效降低了普通节点的硬件复杂性和成本。但是,固定簇头的方法会削弱系统的负载均衡以及健壮性。为了解决这个问题,提出了一种基于自适应退避策略的簇头调度方案,该方案通过适当增加冗余度实现传感节点的k覆盖,增强了网络的健壮性。同时,依赖于地理信息和剩余电池能量信息,簇头节点通过自主周期性睡眠来保证系统负载的均衡分配,延长网络生存期。