Wireless sensor networks for healthcare: A survey

Becoming mature enough to be used for improving the quality of life, wireless sensor network technologies are considered as one of the key research areas in computer science and healthcare application industries. The pervasive healthcare systems provide rich contextual information and alerting mechanisms against odd conditions with continuous monitoring. This minimizes the need for caregivers and helps the chronically ill and elderly to survive an independent life, besides provides quality care for the babies and little children whose both parents have to work. Although having significant benefits, the area has still major challenges which are investigated in this paper. We provide several state of the art examples together with the design considerations like unobtrusiveness, scalability, energy efficiency, security and also provide a comprehensive analysis of the benefits and challenges of these systems.     

Wireless sensor networks: a survey

This paper describes the concept of sensor networks which has been made viable by the convergence of micro-electro-mechanical systems technology, wireless communications and digital electronics. First, the sensing tasks and the potential sensor networks applications are explored, and a review of factors influencing the design of sensor networks is provided. Then, the communication architecture for sensor networks is outlined, and the algorithms and protocols developed for each layer in the literature are explored. Open research issues for the realization of sensor networks are also discussed.     

Wireless sensor networks for emergency navigation

In an emergency, wireless network sensors combined with a navigation algorithm could help safely guide people to a building exit while helping them avoid hazardous areas. We propose a distributed navigation algorithm for emergency situations. At normal time, sensors monitor the environment. When the sensors detect emergency events, our protocol quickly separates hazardous areas from safe areas, and the sensors establish escape paths. Simulation and implementation results show that our scheme achieves navigation safety and quick convergence of the navigation directions. We based our protocol on the temporally ordered routing algorithm for mobile ad hoc networks. TORA assigns mobile nodes temporally ordered sequence numbers to support multipath routing from a source to a specific destination node.     

Wireless visual sensor networks for smart city applications:A relevance-based approach for multiple sinks mobility

Nowadays, the major cities of the world have to solve problems that were unthinkable in past decades. Due to the population growing rate, new issues are still arising, but technology can be used to address such issues and improve life quality in big cities. In that scenario, surveillance is a highly desired service and most governments are already using different types of devices to provide high levels of security. Wireless Visual Sensor Networks (WVSN) can be used to monitor every part of a city without the cost of running cables all over it. However, there must be an efficient way to gather all information collected by the sensors and cameras, with reduced energy consumption and average latency. This work proposes a new algorithm to position multiple mobile sinks in WVSN deployed along roads and streets. A relevance-based approach was designed to position sinks closer to source nodes with higher sensing relevance, since they are expected to transmit more data packets. The proposed algorithm can detect forbidden and disconnected zones, making sure sinks will be positioned in permitted areas, which makes this approach very suitable for realistic smart city applications.     

无线传感器网络与路由算法

规则的无线传感器网络结构具有提高网络容量和增强网络可配置能力的特点,路由寻址上也具有独特的优势.对于如何组建规则拓扑的无线传感器网络提出一种虚拟层次化的组网方式,详细描述了规则拓扑的组网过程.同时为了利用规则拓扑在路由上的优势,提出了一种新的基于凹凸区域策略的维序路由协议.路由算法能够解决路由空洞,同时可以使得路由跳数...     

一种自适应无线传感器网络路由协议

无线传感器网络应用场合拓扑结构复杂,针对特定路径数据双向传输的需求,提出了一种加权的自适应无线传感器网络路由协议,并针对协议建立了相应的仿真模型.仿真结果表明根据网络规划确认的权值所建立的路由,由权值决定下一跳,达到了适应不同的拓扑结构的目的.同时加权结点位置变化时,无需向全网广播数据,只要修改局部路由,降低了因结点移动而再路由所产生的通信量.     

Wireless micromachined ceramic pressure sensor for high-temperature applications

In high-temperature applications, such as pressure sensing in turbine engines and compressors, high-temperature materials and data retrieval methods are required. The microelectronics packaging infrastructure provides high-temperature ceramic materials, fabrication tools, and well-developed processing techniques that have the potential for applicability in high-temperature sensing. Based on this infrastructure, a completely passive ceramic pressure sensor that uses a wireless telemetry scheme has been developed. The passive nature of the telemetry removes the need for electronics, power supplies, or contacts to withstand the high-temperature environment. The sensor contains a passive LC resonator comprised of a movable diaphragm capacitor and a fixed inductor, thereby causing the sensor resonant frequency to be pressure-dependent. Data is retrieved with an external loop antenna. The sensor has been fabricated and characterized and was compared with an electromechanical model. It was operated up to 400/spl deg/C in a pressure range from 0 to 7 Bar. The average sensitivity and accuracy of three typical sensors are: -141 kHz Bar/sup -1/ and 24 mbar, respectively.     

Wireless sensor networks and human comfort index

Conventional wireless home automation networks (WHANs) incorporate embedded wireless sensors and actuators that monitors and control home living environment. WHAN's primary goal is to maintain user comfort and efficient home management. Conventional WHAN lacks “intelligence” in terms of managing compound human comfort, and it deals with multitude of human comfort factors individually instead of collectively. This paper presents wireless sensor networks-based Human Comfort Ambient Intelligence system. A fuzzy-rule-based system for the measurement of human comfort index in a living space is presented. The system is evaluated and tested with simulated and empirical data. It explores the complex relationship between multiple comfort factors. The comfort factors considered here include thermal comfort, visual comfort, indoor air comfort and acoustical comfort.     

无线磁阻传感器网络停车检测技术研究

随着机动车保有量的高速增长,停车混乱问题日益严重,各大中城市对停车实时监控及管理有迫切的建设需求。为了构建基于无线传感器网络的大规模、低成本、低功耗的停车管理系统,本文基于磁场干扰车辆检测原理,提出了一种停车检测算法,实际应用表明该算法车辆检测精度高,达到了设计要求。     

A wireless sensor networks MAC protocol for real-time applications

Wireless sensor networks (WSN) are designed for data gathering and processing, with particular requirements: low hardware complexity, low energy consumption, special traffic pattern support, scalability, and in some cases, real-time operation. In this paper we present the virtual TDMA for sensors (VTS) MAC protocol, which intends to support the previous features, focusing particularly on real-time operation. VTS adaptively creates a TDMA arrangement with a number of timeslots equal to the actual number of nodes in range. Thus, VTS achieves an optimal throughput performance compared to TDMA protocols with fixed size of frame. The frame is set up and maintained by a distributed procedure, which allows sensors to asynchronously join and leave the frame. In addition, duty cycle is increased or decreased in order to keep latency constant below a given deadline. Therefore, a major advantage of VTS is that it guarantees a bounded latency, which allows soft real-time applications.

电机定子温度在线监测的无线传感器网络节点设计

针对电机复杂的结构,提出了将无线传感器网络应用到电机定子绕组温度在线监测中,克服了传统在线监测网络的局限性.深刻剖析了铂电阻三线法测温的原理和基于检温计Pt100与可编程片上系统(PSoC)的传感器节点的硬件设计过程,其性能可以满足无线传感器网络节点对功耗的要求,在此基础之上设计了温度传感器节点的软件.实验结果表明:该温度传感器节点能有效地分析和校正误差,测温准确,为组建电机定子温度在线监测的无线传感器网络奠定了基础.     

基于博弈理论的无线传感器网络融合路由

主要研究了无线传感器网络路由路径的链路质量及节点剩余能量对网络整体可靠性及能效的影响,提出了无线传感器网络数据融合可靠路由的博弈论模型。该模型的求解属于NP问题,论文还提出了一种基于节点效用进行路由选择的分布式实现算法。仿真结果表明该算法能提高网络路由路径的可靠度和能效性。     

无线传感器网络SPIN协议的改进及验证

在无线传感器网络中,对SPIN协议的研究主要是通过仿真进行的,很少有对其进行形式化验证.本文在SPIN协议的基础上进行改进得到了适用于有损网络的协议--SPIN-E协议,并使用有色Petri网对SPIN-E协议进行形式化建模,通过CPN Tools对协议的活性、可达性、有界性等特性进行了分析和验证.     

基于TePA的无线传感器网络安全方案

针对无线传感器网络的安全需求, 结合TePA技术提出了一种基于TePA的无线传感器网络安全方案。该方案简化了TePA技术的身份认证分组和分组字段, 解决了无线传感器网络在传感器节点接入和密钥协商的问题。采用改进的BSW逻辑验证了协议, 并从协议安全性和网络性能方面分析了方案, 结果表明方案能抵抗中间人攻击和重放攻击, 并适合无线传感器网络。     

基于Voronoi的无线传感器网络栅栏覆盖策略

在栅栏覆盖研究中,针对节点部署区域存在无法被监测到的穿越路径的问题,将[Voronoi]图引入栅栏覆盖,划分整个部署区域,提出了基于[Voronoi]图的无线传感器网络栅栏覆盖策略,并监测部署区域是否存在栅栏覆盖空洞,以决定节点是否通过有限移动重新部署空洞区域,实现了对栅栏部署区域的有效覆盖。仿真实验结果表明,该算法提高了对监测区域的覆盖质量,以较低能耗和较少节点构建栅栏,达到预期覆盖要求。     

基于GPS的无线传感器网络时间同步技术

在无线传感器网络测试系统中,为了对测试对象进行准确的测试,时间同步技术至关重要。根据GPS授时原理,提出了利用GPS秒脉冲对同步控制系统进行触发,并无线广播同步触发信号,同时,各传感器节点通过接收同步触发信号,进行时钟同步触发、时钟校准,以及对测试事件触发的同步采集。通过验证,各传感器节点之间的事件同步触发误差为1μs左右,并具有很高的可靠性,可广泛应用于航空、航海等工程测试领域。     

Wireless sensor networks: a survey on recent developments and potential synergies

Wireless sensor network (WSN) has emerged as one of the most promising technologies for the future. This has been enabled by advances in technology and availability of small, inexpensive, and smart sensors resulting in cost effective and easily deployable WSNs. However, researchers must address a variety of challenges to facilitate the widespread deployment of WSN technology in real-world domains. In this survey, we give an overview of wireless sensor networks and their application domains including the challenges that should be addressed in order to push the technology further. Then we review the recent technologies and testbeds for WSNs. Finally, we identify several open research issues that need to be investigated in future. Our survey is different from existing surveys in that we focus on recent developments in wireless sensor network technologies. We review the leading research projects, standards and technologies, and platforms. Moreover, we highlight a recent phenomenon in WSN research that is to explore synergy between sensor networks and other technologies and explain how this can help sensor networks achieve their full potential. This paper intends to help new researchers entering the domain of WSNs by providing a comprehensive survey on recent developments.     

Wireless video sensor networks for sparse, resource-constrained, multi-robot teams

Small-size robots provide access and maneuverability in the tight confines of highly rubbled and uncertain environments such as those encountered in Urban Search and Rescue (USAR). Small size also provides easy portability and deployability and the potential for redundancy through multi-robot teaming. Unfortunately, small size does not diminish the data demands of these applications, such as high-resolution imagery and other forms of high bandwidth data. Furthermore, achieving redundancy in tight environments requires wireless operation to avoid the entanglement of tethers, but wireless communication links have proven unreliable in such environments. The net effect of this is a set of robust networking requirements that include high bandwidth, low latency, and low power with multi-hop routing in a sparse and highly volatile network configuration, which has been collectively difficult to achieve. Our metric for benchmarking these requirements is a stream of uncompressed 320 ×  240, 24-bit color images updated at 1 frame per second (roughly 1.8 Mbps - image compression is not the focus of this research as it only serves to increase the possible resolution or frame rate). No existing ad hoc wireless sensor network approaches have been able to achieve these requirements. Wi-Fi requires high power and size and does not have the latency, while Zig-bee does not have the bandwidth. Instead, this work focuses on augmenting the Bluetooth protocol, which is master/slave based, with a hybrid, multi-hop routing protocol. Bluetooth has the desired low power and high bandwidth characteristics, but lacks multi-hop routing and rapid recovery. In this paper, a hybrid routing protocol for ad hoc multi-robot networking is described that features: (1) high-bandwidth, (2) low power, and (3) low latency of data traffic for sparse, highly volatile networks—exactly what is required for large teams of highly distributed, small-scale robots. Furthermore, this paper compares simulations and robot implementations of different routing protocols over Bluetooth sensor networks and demonstrates the viability of our protocol as a wireless network solution for multi-robot teams characterized by high mobility in difficult RF environments. To the best of our knowledge, the work presented in this paper is the first attempt at comparison of different routing protocols for real robots with physical experiments over Bluetooth sensor networks.     

无线传感器网络技术的研究与应用

主要介绍了无线传感器网络研究中所涉及到的关键性问题,特别针对当前公交信息采集及传递过程中的问题进行了详细的探讨,介绍了一种基于测距无线传感器网络的相应解决方案,具有较好的应用参考价值。