基于无线传感网络的停车场管理系统

This paper introduces a parking management system based on a wireless sensor network developed by our group. The system consists of a large amount of parking space monitoring nodes, a few parking guiding nodes, a sink node and a management station. All the nodes exchange information with each other through wireless communication. The prototype of the parking management system has been implemented and the preliminary test results show that the performance of the system can satisfy the requirements of the application.     

一种输出功率分级的无线传感网络数据收集机制

The data gathering manner of wireless sensor networks, in which data is forwarded towards the sink node, would cause the nodes near the sink node to transmit more data than those far from it. Most data gathering mechanisms now do not do well in balancing the energy consumption among nodes with different distances to the sink, thus they can hardly avoid the problem that nodes near the sink consume energy more quickly, which may cause the network rupture from the sink node. This paper presents a data gathering mechanism called PODA, which grades the output power of nodes according to their distances from the sink node. PODA balances energy consumption by setting the nodes near the sink with lower output power and the nodes far from the sink with higher output power. Simulation results show that the PODA mechanism can achieve even energy consumption in the entire network, improve energy efficiency and prolong the network lifetime.     

有源传感网络中目标跟踪的传感器调度方法

Wireless sensor network (WSN) of active sensors suffers from serious inter-sensor interference (ISI) and imposes new design and implementation challenges. In this paper, based on the ultrasonic sensor network, two time-division based distributed sensor scheduling schemes are proposed to deal with ISI by scheduling sensors periodically and adaptively respectively. Extended Kalman filter (EKF) is used as the tracking algorithm in distributed manner. Simulation results show that the adaptive sensor scheduling scheme can achieve superior tracking accuracy with faster tracking convergence speed.     

无线传感网络中使用动态代理的节点收敛算法

This paper proposes fault tolerant algorithms for routing mobile agents in a single channel wireless sensor network which cover every node in the network. These algorithms use local knowledge (assume no knowledge of global deployment or topology, etc). We propose the algorithms and show mathematical analysis to support our claims. The paper ends with simulation studies and discussion of results.     

无线传感网络中的目标分类融合

In wireless sensor networks, target classification differs from that in centralized sensing systems because of the distributed detection, wireless communication and limited resources. We study the classification problem of moving vehicles in wireless sensor networks using acoustic signals emitted from vehicles. Three algorithms including wavelet decomposition, weighted k-nearest-neighbor andDempster-Shafer theory are combined in this paper. Finally, we use real world experimental data to validate the classification methods. The result shows that wavelet based feature extraction method can extract stable features from acoustic signals. By fusion with Dempster's rule, the classification performance is improved.     

距离交会算法在无线传感网络节点定位中的应用

Knowing the locations of nodes in wireless sensor networks (WSN) is essential for many applications. Nodes in a WSN can have multiple capabilities and exploiting one or more of the capabilities can help to solve the localization problem. In this paper, we assume that each node in a WSN has the capability of distance measurement and present a location computation technique called linear intersection for node localization. We also propose an applied localization model using linear intersection and do some concerned experiments to estimate the location computation algorithm.     

On localization with robust power control for safety critical wireless sensor networks

A hybrid methodology is proposed for use in low power, safety critical wireless sensor network applications, where quality-of-service orientated transceiver output power control is required to operate in parallel with radio frequency-based localization. The practical implementation is framed in an experimental procedure designed to track a moving agent in a realistic indoor environment. An adaptive time synchronized approach is employed to ensure the positioning technique can operate effectively in the presence of dataloss and where the transmitter output power of the mobile agent is varying due to power control. A deterministic multilateration-based positioning approach is adopted and accuracy is improved by filtering signal strength measurements overtime to account for multipath fading. The location estimate is arrived at by employing least-squares estimation. Power control is implemented at two separate levels in the network topology. First, power control is applied to the uplink between the tracking reference nodes and the centralized access point. A number of algorithms are implemented highlighting the advantage associated with using additional feedback bandwidth, where available, and also the need for effective time delay compensation. The second layer of power control is implemented on the uplink between the mobile agent and the access point and here quantifiable improvements in quality of service and energy efficiency are observed. The hybrid paradigm is extensively tested experimentally on a fully compliant 802.15.4 testbed, where mobility is considered in the problem formulation using a team of fully autonomous robots.     

Energy-efficient multipath routing in wireless sensor network considering wireless interference

Due to the energy and resource constraints of a wireless sensor node in a wireless sensor network (WSN), design of energy-efficient multipath routing protocols is a crucial concern for WSN applications. To provide high-quality monitoring information, many WSN applications require high-rate data transmission. Multipath routing protocols are often used to increase the network transmission rate and throughput. Although large-scale WSN can be supported by high bandwidth backbone network, the WSN remains the bottleneck due to resource constraints of wireless sensors and the effects of wireless interference. In this paper, we propose a multipath energy-efficient routing protocol for WSN that considers wireless interference. In the proposed routing protocol, nodes in the interference zone of the discovered path are marked and not allowed to take part in the subsequent routing process. In this way, the quality of wireless communication is improved because the effects of wireless interference can be reduced as much as possible. The network load is distributed on multiple paths instead of concentrating on only one path, and node energy cost is more balanced for the entire wireless network. The routing protocol is simulated in NS2 software. Simulation result shows that the proposed routing protocol achieves lower energy cost and longer network lifetime than that in the literature.     

一个无线传感网络时间同步模拟器

Time synchronization is a critical middleware service of wireless sensor networks. Researchers have already proposed some time synchronization algorithms. However, due to the demands for various synchronization precision, existing time synchronization algorithms often need to be adapted. So it is necessary to evaluate these adapted algorithms before use. Software simulation is a valid and quick way to do it. In this paper, we present a time synchronization simulator, Simsync, for wireless sensor networks. We decompose the packet delay into 6 delay components and model them separately. The frequency of crystal oscillator is modeled as Gaussian. To testify its effectiveness, we simulate the reference broadcast synchronization algorithm (RBS) and the timing-sync synchronization algorithm (TPSN) on Simsync. Simulated results are also presented and analyzed.     

无线传感网络中安全密钥管理机制

Recent advancements in wireless communication and microchip techniques have accelerated the development of wireless sensor networks (WSN). Key management in WSN is a critical and challenging problem because of the inner characteristics of sensor networks: deployed in hostile environments, limited resource and ad hoc nature. This paper investigates the constraints and special requirements of key management in sensor network environment, and some basic evaluation metrics are introduced. The key pre-distribution scheme is thought as the most suitable solution for key management problem in wireless sensor networks. It can be classified into four classes: pure probabilistic key predistribution, polynomial-based, Blom′s matrix-based, and deterministic key predistribution schemes. In each class of methods, the related research papers are discussed based on the basic evaluation metrics. Finally, the possible research directions in key management are discussed.     

非打扰式无线传感器网络测试仪的设计与实现

无线传感器网络的测试工具对于传感器网络的深入研究和应用具有重要意义。提出了一种非打扰式的无线传感器网络测试方法,并介绍了基于该方法的无线传感器网络测试仪的设计思路和详细实现。该测试仪采用可编程逻辑阵列(FPGA)高速采集传感器节点的内部互连信息,并将采集的信息通过额外网络传输到测试服务器进行集中处理,还原节点状态信息和获取整个无线网络的通信情况,避免了对传感器网络节点运行和无线通信的影响。实验测试表明,该测试仪可以很好地获取节点状态,并在数据采集的过程中不干扰节点的正常工作。     

一种无线传感器网络的节能路由算法

提出一种基于逆向多播树的路由算法,该算法依赖局部信息建立基于逆向多播树的路由拓扑结构。利用该算法对不同类型的传感器数据建立不同的路由策略并进行传输。实验测试表明,该路由算法能有效地减少网络通信量,并具有较好的节能性能。     

一种TDMA无线传感器网络MAC协议能量有效性分析

经典轮询协议作为一种TDMA型MAC协议,符合无线传感器网络节约能量的要求,但在网络伸缩性上有所不足。在此基础上得出一种更适用于无线传感器网络的Controllable Threshold Polling MAC协议(CTP-MAC),使得网络能够自主完成时隙分配;结合概率母函数的方法,建立网络能量有效性的分析模型,得到平均功率的近似计算公式,对经典门限服务轮询协议和C"I'P-MAC进行分析。通过仿真实验,验证了分析模型的有效性。     

无线传感器在智能配电网中的通信网络设计

智能配电网可以有效地提高配电系统的供电质量、实现分布式电源的并网优化运行与配电设备的高效运转、完成与用户之间的有效互动。无线传感器网络（Wireless Sensor Network,WSN）具有建设成本低、快速自组网等特点,在智能配电网通信系统中具有广阔的应用前景。论文通过总结智能配电终端在配电网的分布特征以及WSN在电力系统中的应用现状,分析了WSN的网络结构及其在智能配电网中的应用特点,并以此为基础给出了智能配电网WSN的设计原则。根据该原则设计了智能配电网WSN的分层体系结构,包括终端采集网、汇聚网和信息接入网。智能配电网的通信系统通常由多种通信方式组成,本文给出了与其他通信方式联合组网的设计方案,该方案通过构建业务终端层、接入层、骨干层和配电主站层,可以有效地扩展智能配电通信网的通信范围,提高智能配电网的网络数据完整性。     

基于身份的无线传感器网络密钥系统

无线传感器络（WSN）是一类由众多微型传感器节点通过自组织的方式构成的网络。随着在军事、环境监测等方面的应用逐渐成为现实,其有效和安全通信问题由于自身的特性（如能量、计算能力和节点存储资源等的局限性）而显得更加突出。本文首先比较详细地介绍了无线传感器网络安全结构及其面临的问题;其次重点讨论了无线传感器网络密钥系统相关的研究现状;然后给出了一种有效的基于身份的无线传感器网络密钥系统方案及与其它方案的仿真比较实验。仿真实验结果表明,我们方案较其它密钥系统方案在处理时间和节点存储需求方面具有优势。     

一种混合轻量型无线传感器网络公钥密码方案

将基于身份的公钥机制与轻量级CA(Certificate Authority)思想相结合,构建了一个基于身份及轻量级CA混合模型的传感器网络密码方案。该方案既克服了基于身份公钥机制中的第三方密钥托管问题,又简化了基于传统证书机制中产生、验证及管理公钥的复杂性。分析表明,方案可使公钥产生轻量化,公钥验证轻量化,密钥管理无需证书,且安全性高,可抵御无线环境下易于实施的多种攻击,适用于保障资源受限的无线网络中数据的机密性、完整性和不可否认性。     

嵌入式无线传感器网络节点的设计

介绍了以超低功耗单片机MSP430F149为核心，结合外围传感器和无线收发模块的传感器网络节点的软、硬件设计与实现方案，MSP430F149控制传感器采集环境中的温度、湿度和振动数据，并对原始数据进行初步处理，再由无线收发模块将数据发送给相邻节点，一级级转发最终发送回服务器，实现对环境的监测。     

无线传感器网络操作系统TinyOS的移植

TinyOS系统以其组件结构模型、事件驱动、简易的编程环境等优点成为目前最受关注的无线传感器网络操作系统,而CC2430以其高性能、低成本、低功耗被广泛应用于无线传感器网络节点,但TinyOS不支持CC2430芯片,因此在分析TinyOS基本原理、NesC编程语言实现机制及其编译过程的基础上,介绍了基于CC2430的TinyOS及NesC语言的移植方法,完成了NesC语言、CC2430的Timer组件、Uart组件、ADC组件和RF组件的移植,并测试了各组件的移植效果。在移植的基础上,进行了基于优先级的任务调度机制的改进和星形网的组建。实验测试结果表明,两项扩展应用均已开发成功。     

簇状树形无线传感器网络系统级设计分析

簇状树形网络在无线传感器网络应用中大量存在,对此种网络的协议进行系统级建模可以有效地提高设计的灵活性,可以针对不同的应用进行快速配置.针对一种工业无线传感器网络协议,提出了一种典型的簇状树形网络的系统级建模方法,并在系统的可靠性、低功耗、时延等不同的方面进行了设计评估.实际工厂的部署和实验表明,采用系统级分析,可以快速高效地对系统的参数进行调整,达到网络设计的需求.     

无线传感器网络数据融合模型研究

无线传感器网络是一种全新的技术,能够广泛应用于恶劣环境和军事领域中。传感器网络在数据收集中,为减少冗余数据的传输耗能,降低延迟,需要采用数据融合技术。分析和介绍了传感器网络跟踪级与属性级两种融合模型结构,提出了一种基于多Agent的数据融合模型。