基于IEEE 802.15.4的无线传感器网络的设计与实现

利用基于IEEE 802.15.4的IP-Link1200模块,设计并实现了能够实时接入现有蜂窝网络的无线传感器网络的验证系统。该方案工作于900 MHz或1 800 MHz的GSM(全球移动通信系统)网络的SMS(短消息业务)平台,把从目标区域采集到的温湿度参数传送给位于远程的任务管理中心。用户只需用普通的支持短消息的手机,向任务管理中心发送固定格式的短消息,就可以实时地获得任意一指定节点的温湿度参数。另外,也可以通过Internet打印历史报表。     

无线传感器网络的体系结构

在对无线传感器应用特征进行分析的基础上,总结了无线传感器体系结构设计的要素,讨论了无线传感器网络的二维体系结构和组网方式.通过与传统Ad hoc网络的对比,归纳了无线传感器网络在各层各面设计的特点.文章认为虽然传统的传感器的应用方向主要在军事领域,但在民用领域也存在着广阔的前景.     

基于IEEE 802.15.4的传感器网络性能研究

本文针对传感器网络协议关心的设计指标,分析了IEEE 802.15.4应用于传感器网络的有效性.文中在ns-2仿真平台上建立了较为精确的能量模型,仿真分析了负载、占空比、工作/睡眠切换频率和节点数对传感器网络性能的影响,为实际应用中设置合理的参数以及进一步改进MAC协议提供了依据.还对网络的能耗、时延和可升级能力进行了定量研究.     

基于FPGA的无线传感器网络自组网设计

本论文主要内容是针对无线传感器网络的自组网络的研究,提出了一种基于FPGA的高速运算处理的对等网络节点的自组网络的设计方法,用于构建WSN应用的专用设计IP核,适用于各种不同的WSN网络层路由协议和各类不同的WSN应用场景。     

无线传感器网络的自组织机制研究

无线传感器网络的自组织包含不依赖于固定通信基础设施的有规则联系和运动,本文在特定应用中研究这一过程.在定性分析无线传感器网络的自组织特性之后,提出自组织度和自组织单位能耗的自组织评价方法,在典型应用中以此量化分析无线传感器网络的自组织演化机制.仿真表明,在特定应用中的无线传感器网络表现出孕育、发育、成熟、衰退和死亡的自组织过程,自组织能耗依赖于特定的部署方式和无线模型.     

无线传感器网络与自组织网络的研究现状

传感器网络综合了传感器技术、嵌入式计算技术、分布式信息处理技术和无线通信技术,是计算机科学技术的一个新的研究领域;自组织网络是一种移动、多跳、自律式系统,两者均具有十分广阔的应用前景.文章对传感器网络和自组织网络的概念、特征和发展动态等问题进行了介绍,重点分析了目前这两种网络的关键技术和研究现状.文章认为:传感器网络在特殊领域有着传统技术不可比拟的优势,而无线自组织网络通过临时组网的方式在恶劣环境中支持移动节点之间的无线传输,应用范围广阔.对这些网络的研究是中国未来高技术民用和军事发展的需要.     

基于无线自组网技术的监控系统设计

设计一套基于无线自组网技术的监控系统,旨在对运输及库存中的重要产品进行远距离监控,避免繁琐的人工管理过程。从通信组网、硬件设计方面介绍了初步方案设计,拟利用短距离、低耗的WSN实现相对静止空间内的组网,利用MANET实现相对运动时的组网,以实现全国范围内的,信息传递时间小于5分钟的动态监控网络。     

无线传感器网络的节点自定位技术

文章对无线传感器网络的节点定位机制与算法进行了介绍,并对基于测距的和不基于测距的两大类方法进行了分析对比.文章认为节点定位是无线传感器网络的一项关键技术,对于无线传感器网络的许多应用来说节点位置信息都是必须的基本信息,虽然目前已有不少节点定位技术,但仅仅是一些初步的研究成果,距离无线传感器网络的整体优化目标还很不够,需要继续深入研究开发,提出更多的高效算法,促进无线传感器网络进一步的普及应用.     

基于无线传感器网络的农业环境监测系统

针对当前农业环境在线监测的需要,提出了一种利用具有自组织特性的无线传感器网络(wireless sensor networks,WSN)对温度、土地湿度和土壤的PH值等环境变量进行在线监测的方法.该方法采用了对等式网络体系结构、低功耗微小网络节点、基于拓扑树的网络初始化配置算法.实验测试表明节点能够有效地采集和处理数据,并可以在节点间成功地进行通信.     

无线传感器网络自身定位算法研究

无线传感器网络是一种特殊的无线自组织网络,在很多领域有着广泛的应用,定位是他的一项支撑技术。GPS是一种传统的定位技术,但他不适用于传感器网络节点的定位。近些年,国内外提出了很多有价值的算法,总结了现有的算法,通过分析认为两种求精算法Robust positioning和N-hop multilateration是比较优秀的算法,最后提出了今后还要做的工作。     

Emergency access mechanism in IEEE 802.15.4 for wireless body area sensor networks

IEEE 802.15.4 protocol has attracted much attention in research and industrial communities as candidate technology for wireless body area sensor networks (WBASNs). IEEE 802.15.4 supports the exclusive use of a wireless channel through guaranteed time slot (GTS). However, on one hand, bandwidth underutilization rate may be lower because of the variance between the guaranteed bandwidth and the arrival rate. On the other hand, the waiting time for transmitting emergency notification is getting longer when the GTSs assigned to the nodes increase in WBASNs. To solve these problems, in this article, a new scheme is proposed to reduce transmission delay for the alarm notification in emergent situations. Simulation results are presented to validate the efficiency of the proposed scheme by comparing it with the medium access control (MAC) protocol of IEEE 802.15.4.     

移动Sink传感网中基于IEEE 802.15.4的拓扑控制与路由

针对查询驱动的移动Sink无线传感器网络,基于IEEE 802.15.4标准,提出了一个联合簇树组网和移动路由的跨层协议设计方案。以能耗、网络连通度、负载均衡和子树深度等指标为评价因子,在多目标优化模型下定义了一个拓扑综合评价函数,构建稳定的最优簇树网络结构;改进了IEEE 802.15.4 MAC中基于信标帧调度的分布式睡眠同步算法,维护较低占空比下的网络同步与拓扑修正;利用拓扑形成过程中依"最早信标帧"、"最好链路"、"最小层次"3种准则确立的父子关系,建立移动Sink与N-Hop范围内节点的双向路由路径。最终将上述MAC层的拓扑控制方案与网络层的查询路由方法完整实现于TinyOS协议栈中。实验结果表明,评价函数能够有效地反映组网质量,N-Hop后验式路由结合睡眠同步机制,在"最好链路"拓扑下表现出较高的能量效率。     

基于IEEE802.15.4标准的软件无线电技术研究

随着微机电、无线通信等关键支撑技术研究的持续发展,无线传感器网络的研究也进一步深化.无线传感器网络适用的领域越来越广,有人适时提出多媒体无线传感器网络的概念,以满足人们在传感器网络平台下对图像、语音,甚至视频数据等信息传输的需求.如何实现无线传感器网络在多种应用环境及同一环境下多工作模式的智能化转换,软件无线电技术无疑是一种较好选择.就软件无线电技术引入传感器网络进行一些探讨,对PHY层MAC层的技术进行了研究.最后,展示了一个简单的传感器网络软件无线电演示平台.     

基于IEEE 802.15.4的无线USB适配器设计与实现

在无线传感器监测网络中,通常需要一个网络协调器将各终端节点采集的数据上传给监控中心,但是在有些场合用网络协调器组网很不方便。为此,本文介绍了利用USB接口技术优势结合IEEE802.15.4标准协议特点开发的无线USB适配器,详细阐述了该设备无线收发器模块、USB与串口数据转换模块等部分软、硬件设计原理,并通过组网进行了实际的测试。该设备的设计解决了现场监测环境中一系列组网复杂、开发成本过高等实际问题。     

A survey of IEEE 802.15.4 effective system parameters for wireless body sensor networks

Wireless body sensor networks are offered to meet the requirements of a diverse set of applications such as health‐related and well‐being applications. For instance, they are deployed to measure, fetch and collect human body vital signs. Such information could be further used for diagnosis and monitoring of medical conditions. IEEE 802.15.4 is arguably considered as a well‐designed standard protocol to address the need for low‐rate, low‐power and low‐cost wireless body sensor networks. Apart from the vast deployment of this technology, there are still some challenges and issues related to the performance of the medium access control (MAC) protocol of this standard that are required to be addressed. This paper comprises two main parts. In the first part, the survey has provided a thorough assessment of IEEE 802.15.4 MAC protocol performance where its functionality is evaluated considering a range of effective system parameters, that is, some of the MAC and application parameters and the impact of mutual interference. The second part of this paper is about conducting a simulation study to determine the influence of varying values of the system parameters on IEEE 802.15.4 performance gains. More specifically, we explore the dependability level of IEEE 802.5.4 performance gains on a candidate set of system parameters. Finally, this paper highlights the tangible needs to conduct more investigations on particular aspect(s) of IEEE 802.15.4 MAC protocol. Copyright © 2015 John Wiley & Sons, Ltd.     

Spoofing detection in IEEE 802.15.4 networks based on received signal strength

The shared medium used in wireless networks makes them vulnerable to spoofing attacks, in which an adversary masquerades as one or more legitimate nodes to disturb normal operation of the network. In this paper we present a novel spoofing detection method for static IEEE 802.15.4 networks based on spatial correlation property of received signal strength (RSS). While most existing RSS based techniques directly process RSS values of the received frames and rely on multiple traffic air monitors (AMs) to provide an acceptable detection performance, we extract features of RSS streams to reduce data redundancy and provide a more distinguishable representation of the data. Our algorithm employs two features of RSS streams, summation of detailed coefficients (SDCs) in discrete Haar wavelet transform (DHWT) of the RSS streams and the ratio of out-of-bound frames. We show that in a typical scenario, a single AM with SDC as detection parameter, can theoretically outperform a system with 12 AMs which directly applies RSS values as detection parameter. Using ratio of out-of-bound frames facilitates detection of high rate attacks. In addition, we suggest adaptive learning of legitimate RSS values which enhances the robustness of the attack detector against environmental changes. Using both magnitude and frequency related features, we achieved high detection performance with a single AM; this enables development of preventive measures for spoofing attacks. The performance of our approach was evaluated through an IEEE 802.15.4 testbed in an office environment. Experimental results along with theoretical analysis show that the proposed method outperforms the existing RSS-based spoofing detection solutions. Using a single AM, we were able to attain 94.75% detection rate (DR) with 0.56% false positive rate (FPR). For 4 AMs, the results improved to 99% DR and 0% FPR.     

基于IEEE802．15．4实现无线语音通信

提出一种基于IEEE802.15.4的无线语音通信技术方案,该方案采用TI公司的CC2430芯片进行设计,充分利用CC2430 SoC的性能特点,使用的外围器件很少,很好地实现了短距离无线语音传输,具有成本低,音质较好的优点.     

Performance evaluation of IEEE 802.15.4 sensor networks in industrial applications

Wireless sensor networks have been widely applied in industrial applications especially since the release of IEEE 802.15.4 standard. By participating in an automobile project in which an IEEE 802.15.4 based sensor and actuator network is deployed to measure and control the vibrations of an automotive system, we need to study many metrics of IEEE 802.15.4 sensor networks (e.g., packet delivery rate, latency, and energy consumption) under various sampling rates. In order to provide detailed modeling of hardware and software as well as network behaviors on each sensor node, we conduct plenty of experiments on a SystemC‐based wireless sensor networks simulator IDEA1, which supports the hardware and software co‐simulation of sensor nodes with certain flexibility of abstraction level. Compared with the existing works on performance evaluation of IEEE 802.15.4 protocols, the main contributions of this paper are the comprehensive studies of both beacon‐enabled and nonbeacon‐enabled modes under various parameter settings and the beacon tracking synchronization mechanism in the IEEE 802.15.4 standard, which is ignored in most previous works. Additionally, the in‐depth analysis of simulation results enables us to find the best parameter configurations to different traffic loads and application requirements, which can be used as general experiences for other applications.Copyright © 2014 John Wiley & Sons, Ltd.     

Duty cycle learning algorithm (DCLA) for IEEE 802.15.4 beacon-enabled wireless sensor networks

The current specification of the IEEE 802.15.4 standard for beacon-enabled wireless sensor networks does not define how the fraction of the time that wireless nodes are active, known as the duty cycle, needs to be configured in order to achieve the optimal network performance in all traffic conditions. The work presented here proposes a duty cycle learning algorithm (DCLA) that adapts the duty cycle during run time without the need of human intervention in order to minimise power consumption while balancing probability of successful data delivery and delay constraints of the application. Running on coordinator devices, DCLA collects network statistics during each active duration to estimate the incoming traffic. Then, at each beacon interval uses the reinforcement learning (RL) framework as the method for learning the best duty cycle. Our approach eliminates the necessity for manually (re-)configuring the nodes duty cycle for the specific requirements of each network deployment. This presents the advantage of greatly reducing the time and cost of the wireless sensor network deployment, operation and management phases. DCLA has low memory and processing requirements making it suitable for typical wireless sensor platforms. Simulations show that DCLA achieves the best overall performance for either constant and event-based traffic when compared with existing IEEE 802.15.4 duty cycle adaptation schemes.     

IEEE802.15.4射频接收端系统设计

概述2.4GHz无线接收器物理层规范,对IEEE 802.15.4的射频接收器的结构和性能进行了系统分析,结果表明该系统满足接收要求,且具有较高的抗干扰性.