Body Area Networks: A Survey

Advances in wireless communication technologies, such as wearable and implantable biosensors, along with recent developments in the embedded computing area are enabling the design, development, and implementation of body area networks. This class of networks is paving the way for the deployment of innovative healthcare monitoring applications. In the past few years, much of the research in the area of body area networks has focused on issues related to wireless sensor designs, sensor miniaturization, low-power sensor circuitry, signal processing, and communications protocols. In this paper, we present an overview of body area networks, and a discussion of BAN communications types and their related issues. We provide a detailed investigation of sensor devices, physical layer, data link layer, and radio technology aspects of BAN research. We also present a taxonomy of BAN projects that have been introduced/proposed to date. Finally, we highlight some of the design challenges and open issues that still need to be addressed to make BANs truly ubiquitous for a wide range of applications.     

基于IEEE 802．15．4标准的调制解调技术软件无线电问题研究

随着微机电、无线通信等关键支撑技术研究的持续发展,无线传感器网络研究也进一步得到深化,无线传感器网络适用的领域也越发宽广。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。文章就IEEE 802．15．4标准中的调制解调技术的软件无线电化问题进行一些探讨。     

Security services in group communications over wireless infrastructure, mobile ad hoc, and wireless sensor networks

Group communications in wireless networks has been facilitating many emerging applications that require packet delivery from one or more sender(s) to multiple receivers. Due to insecure wireless channels, group communications are susceptible to various kinds of attacks. Although a number of proposals have been reported to secure group communications, provisioning security in group communications in wireless networks remains a critical and challenging issue. This article presents a survey of recent advances in security requirements and services in group communications in three types of wireless networks, and discusses challenges in designing secure group communications in these networks: wireless infrastructure networks, mobile ad hoc networks, and wireless sensor networks.     

无线传感器网络及其安全问题

文章认为随着无线通信技术和电子器件技术的快速发展,低成本、低功耗、多功能的无线传感器的开发和广泛应用成为可能,但在大多数应用环境中用户对无限传感器网络的安全能力有很高的要求,因此安全成为制约无限传感器网络广泛应用的关键.为此文章探讨了无线传感器网络协议栈各层所面临的安全问题,对解决这些安全问题的关键技术进行了讨论.     

Energy-aware on-demand scatternet formation and routing for Bluetooth-based wireless sensor networks

Bluetooth is a promising short-range wireless communication technology with the characteristics of interference resilience and power efficiency, both desirable for wireless sensor networks. The new Intel Mote sensor devices have Bluetooth technology incorporated as the standard wireless communications interface. When using Bluetooth in applications where multihop routing is required, groups of Bluetooth piconets combine together to form a scatternet. However, most of the existing scatternet formation protocols are designed to facilitate communications between any two pairs of devices, regardless of the actual traffic demand pattern. For wireless sensor network applications with low-duty-cycle traffic patterns, an on-demand scatternet formation protocol can achieve significant power saving by avoiding unnecessary network connectivity. To that end, we introduce an on-demand scatternet and route formation protocol designed specifically for Bluetooth-based wireless sensor networks. Our protocol builds a scatternet on demand, and is able to cope with multiple sources initiating traffic simultaneously. In addition, our energy-aware forwarding nodes selection scheme is based on local information only, and results in more uniform network resource utilization and improved network lifetime. Simulation results show that our protocol can provide scatternet formation with reasonable delay and good load balance, which results in prolonged network lifetime for Bluetooth-based wireless sensor networks.     

Taxonomy and Challenges of the Integration of RFID and Wireless Sensor Networks

Radio frequency identification and wireless sensor networks are two important wireless technologies that have a wide variety of applications in current and future systems. RFID facilitates detection and identification of objects that are not easily detectable or distinguishable by using conventional sensor technologies. However, it does not provide information about the condition of the objects it detects. WSN, on the other hand, not only provides information about the condition of the objects and environment but also enables multihop wireless communications. Hence, the integration of these technologies expands their overall functionality and capacity. This article investigates recent research work and applications that integrate RFID with sensor networks. Four classes of integration are discussed: integrating tags with sensors, integrating tags with WSN nodes and wireless devices, integrating readers with WSN nodes and wireless devices, and a mix of RFID and WSNs. Finally, a discussion of new challenges and future work is presented.     

Cooperative Communications in Resource-Constrained Wireless Networks

Cooperative communications have been proposed to exploit the spatial diversity gains inherent in multiuser wireless systems without the need of multiple antennas at each node. This is achieved by having the users relay each others messages and thus forming multiple transmission paths to the destination. In resource constrained networks, such as wireless sensor networks, the advantages of cooperation can be further exploited by optimally allocating the energy and bandwidth resources among users based on the available channel state information (CSI) at each node. In the first part of this article, we provide a tutorial survey on various power allocation strategies for cooperative networks based on different cooperation strategies, optimizing criteria, and CSI assumptions. In the second part, we identify the similarities between cooperative networks and several sensor network applications that utilize collaboration among distributed sensors to achieve the system goal. These applications include decentralized detection/estimation and data gathering. The techniques developed in cooperative communications can be used to solve many sensor network problems     

Software Defined Radio Technology for Highly Reliable Wireless Communications

This paper introduces the concept of highly dependable wireless communications for wireless robotics based on software defined radio (SDR) technologies. The features and advantages of SDR technologies are initially explained, whereupon the research and development activities of KDDI R&D Laboratories are presented. Advanced applications of SDR for telerobotic control, which require highly reliable wireless communications and for multi-mode wireless sensor networks are proposed as potential markets for wireless robotics and machine to machine communication. Finally, the current status and research issues of SDR are summarized and this paper is concluded.     

EARQ: Energy Aware Routing for Real-Time and Reliable Communication in Wireless Industrial Sensor Networks

Wireless industrial sensor networks are wireless sensor networks which have been adapted to industrial applications. Most techniques for wireless sensor networks can be applied to wireless industrial sensor networks. However, for industrial applications of wireless industrial sensor networks, new requirements such as real-time, reliable delivery need to be considered. In this paper, we propose EARQ, which is a novel routing protocol for wireless industrial sensor networks. It provides real-time, reliable delivery of a packet, while considering energy awareness. In EARQ, a node estimates the energy cost, delay and reliability of a path to the sink node, based only on information from neighboring nodes. Then, it calculates the probability of selecting a path, using the estimates. When packet forwarding is required, it randomly selects the next node. A path with lower energy cost is likely to be selected, because the probability is inversely proportional to the energy cost to the sink node. To achieve real-time delivery, only paths that may deliver a packet in time are selected. To achieve reliability, it may send a redundant packet via an alternate path, but only if it is a source of a packet. Experimental results show that EARQ is suitable for industrial applications, due to its capability for energy efficient, real-time, reliable communications.      

无线传感器网络与其关键技术

文章描述了基于微机电子系统(MEMS)技术,无线通信技术,数字电子技术的无线传感器网络的概念.阐述了无线传感器网络设计的部分关键技术:网络拓扑控制、数据融合和定位技术等,并指出各技术存在的问题,无线传感器网络和传统无线网络有着本质的不同,节能、安全都应是设计时主要考虑的问题.     

基于ZigBee无线传感器网络的实验室监控系统设计

探讨了ZigBee作为一种无线个人区域网络技术的特性,提出了基于ZigBee无线传感器网络的实验室监控系统的设计。该设计能够实现实时可靠的数据传输,并具有良好的弹性与可扩展性,可以有效提升实验室环境的远程监控功能。此低功耗、低数据速率、低复杂度、低成本的网络构型可以作为无线监控领域新的配置方案。     

无线传感器网络中数据链路层和网络层设计

作为无线通信网络的一个新的研究热点,无线传感器网络正以其独有的特点和全新的应用而得到人们的广泛关注.本文简要介绍无线传感器网络的体系结构、节点构成和协议层次.分类阐述了几种典型的数据链路层和网络层的设计方案和设计思想.数据链路层中MAC协议可分为两大类:基于竞争的MAC协议和基于预约的MAC协议;网络层的路由算法也分为两大类:平面路由协议和分级路由协议.最后提出一些研究构想.     

LIS: Localization based on an intelligent distributed fuzzy system applied to a WSN

The localization of the sensor nodes is a fundamental problem in wireless sensor networks. There are a lot of different kinds of solutions in the literature. Some of them use external devices like GPS, while others use special hardware or implicit parameters in wireless communications.In applications like wildlife localization in a natural environment, where the power available and the weight are big restrictions, the use of hungry energy devices like GPS or hardware that add extra weight like mobile directional antenna is not a good solution.Due to these reasons it would be better to use the localization’s implicit characteristics in communications, such as connectivity, number of hops or RSSI. The measurement related to these parameters are currently integrated in most radio devices. These measurement techniques are based on the beacons’ transmissions between the devices.In the current study, a novel tracking distributed method, called LIS, for localization of the sensor nodes using moving devices in a network of static nodes, which have no additional hardware requirements is proposed.The position is obtained with the combination of two algorithms; one based on a local node using a fuzzy system to obtain a partial solution and the other based on a centralized method which merges all the partial solutions. The centralized algorithm is based on the calculation of the centroid of the partial solutions.Advantages of using fuzzy system versus the classical Centroid Localization (CL) algorithm without fuzzy preprocessing are compared with an ad hoc simulator made for testing localization algorithms.With this simulator, it is demonstrated that the proposed method obtains less localization errors and better accuracy than the centroid algorithm.     

QoS provisioning in wireless video sensor networks: a dynamic power management framework

Recent technological advances in microelectronics and nano-systems technologies have made it feasible to equip wireless sensor nodes with small low-cost cameras to capture and transmit video. Wireless video sensor networks are gaining popularity due to numerous potential applications such as video surveillance, environmental and habitat monitoring, and so on. However, due to the limited battery available in wireless video sensor nodes, provisioning of QoS in such a network is a challenging task. We provide a survey on the major issues related to QoS provisioning in wireless video sensor networks and possible solution approaches. A dynamic power management framework is proposed for a wireless video sensor node to improve energy saving performance so that the lifetime of the sensor node can be increased. This framework considers the video traffic arrival process in the sensor node, the sleep and wakeup processes in the camera and wireless transceiver electronics, the queue status, and the wireless channel condition. Performance analysis results show that the proposed mechanism can achieve considerable energy saving in a sensor node while providing a target level of QoS performance.     

Recent and Emerging Topics in Wireless Industrial Communications: A Selection

In this paper we discuss a selection of promising and interesting research areas in the design of protocols and systems for wireless industrial communications. We have selected topics that have either emerged as hot topics in the industrial communications community in the last few years (like wireless sensor networks), or which could be worthwhile research topics in the next few years (for example cooperative diversity techniques for error control, cognitive radio/opportunistic spectrum access for mitigation of external interferences).     

无线传感器网络技术

无线传感器网络是新兴的下一代传感器网络,文章对无线传感器网络技术的兴起和发展,无线传感器网络的基本构成和关键技术,无线传感器网络的应用和发展前景进行了讨论,对可能的技术走向,与现有技术的兼容提出看法和建议.文章认为无线传感器网络尚不成熟,需要进一步研究各种支撑技术.     

普适计算环境下无线传感器网络研究

主要对在普适计算(ubiquitous computing or pervasive computing)环境下的无线传感器网络进行了研究。首先,介绍普适计算和无线传感器网络概念;其次,论述在普适计算环境下,无线传感器网络各项技术的研究,包括:面向普适计算的无线传感器网络中间件研究,无线传感器网络与物联网的融合研究和普适环境下无线传感器网络的各项关键性技术研究,如传感器的功耗问题和节点供电问题。最后:无线传感器网络的一些优点能方便人们更好地实现普适计算中的通信、感知、场景识别等功能,在未来,它将会是实现普适计算的主要途径。     

IEEE 802.15.4: a developing standard for low-power low-costwireless personal area networks

A low-rate wireless personal area network, or LR-WPAN, is a network designed for low-cost very-low-power short-range wireless communications. Until now, the main focus in the wireless industry has been on communications. Until now, the main focus in the wireless industry has been on communication with higher data throughput, leaving out a set of applications requiring simple wireless connectivity with relaxed throughput and latency requirements. LR-WPANs will connect devices that previously have not been networked and allow applications that cannot use current wireless specifications, including applications in fields such as industrial, agricultural, vehicular, residential, medical sensors and actuators. TaskGroup 4 of the IEEE 802.14 Wireless personal Area Network working group is currently working to define a wireless communication standard for LR-WPANs. This article discusses the technical considerations and system requirements necessary when implementing a low-cost low-power wireless personal area network and provides an overview of the unique applications such a technology will enable     

Hybrid energy efficient static routing protocol for homogeneous and heterogeneous large scale WSN

Wireless Networks - Wireless sensor networks consist of a large number of nodes deployed randomly in an area of interest. Theses nodes have sensing, computation, and wireless communications...