Sensor Networks (sensor + network)

Distribution by Scientific Domains
Distribution within Engineering

Kinds of Sensor Networks

  • wireless sensor network


  • Selected Abstracts


    Mobile Agent Computing Paradigm for Building a Flexible Structural Health Monitoring Sensor Network

    COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 7 2010
    Bo Chen
    While sensor network approach is a feasible solution for structural health monitoring, the design of wireless sensor networks presents a number of challenges, such as adaptability and the limited communication bandwidth. To address these challenges, we explore the mobile agent approach to enhance the flexibility and reduce raw data transmission in wireless structural health monitoring sensor networks. An integrated wireless sensor network consisting of a mobile agent-based network middleware and distributed high computational power sensor nodes is developed. These embedded computer-based high computational power sensor nodes include Linux operating system, integrate with open source numerical libraries, and connect to multimodality sensors to support both active and passive sensing. The mobile agent middleware is built on a mobile agent system called Mobile-C. The mobile agent middleware allows a sensor network moving computational programs to the data source. With mobile agent middleware, a sensor network is able to adopt newly developed diagnosis algorithms and make adjustment in response to operational or task changes. The presented mobile agent approach has been validated for structural damage diagnosis using a scaled steel bridge. [source]


    A reliable cooperative and distributed management for wireless industrial monitoring and control

    INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 2 2010
    Dr S. Manfredi
    Abstract This paper is concerned with the analysis, design and validation of a reliable management strategy for industrial monitoring and control over wireless sensor network (WSN). First, we investigate the interactions between contention resolution and congestion control mechanisms in Wireless Industrial Sensor Network (briefly WISN). An extensive set of simulations are performed in order to quantify the impacts of several network parameters (i.e. buffer, sensors reporting rate) on the overall network performance (i.e. reliability, packet losses). This calls for cross-layer mechanisms for efficient data delivery over WISN. Second, a reliable sink resource allocation strategy based on log-utility fairness criteria is proposed. It is shown that the resource sink manager can plan strategies to better allocate the available resource among competing sensors. Finally, the analysis, design and validation of a reliable sinks cooperative control for WISN are introduced. A sufficient condition for wireless network stability in presence of multiple sinks and heterogeneous sensors with different time delays is given and it is used for network parameters design. The stability condition and the resulting cooperative control performance in terms of fairness, link utilization, packet losses, reliability and latency are validated by Matlab/Simulink-based simulator TrueTime, which facilitates co-simulation of controller task execution in real-time kernels and in the wireless network environment. Copyright 2009 John Wiley & Sons, Ltd. [source]


    Distributed intelligence in an astronomical Distributed Sensor Network

    ASTRONOMISCHE NACHRICHTEN, Issue 3 2008
    R.R. White
    Abstract The Telescope Alert Operations Network System (TALONS) was designed and developed in the year 2000, around the architectural principles of a distributed sensor network. This network supported the original Rapid Telescopes for Optical Response (RAPTOR) project goals; however, only with further development could TALONS meet the goals of the larger Thinking Telescope Project. The complex objectives of the Thinking Telescope project required a paradigm shift in the software architecture , the centralised intelligence merged into the TALONS network operations could no longer meet all of the new requirements. The intelligence needed to be divorced from the network operations and developed as a series of peripheral intelligent agents, distributing the decision making and analytical processes based on the temporal volatility of the data. This paper is presented as only one part of the poster from the workshop and in it we will explore the details of this architecture and how that merges with the current Thinking Telescope system to meet our project goals. ( 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Exploiting Context-Awareness in Cluster-Based Wireless Sensor Networks

    IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 5 2009
    Md Enamul Haque Non-member
    Abstract Most of the wireless sensor network's (WSN's) applications require getting accurate information as well as uninterrupted, prolonged service life. Among the constituting elements of WSN, an efficient routing protocol plays a significant role in attaining such service requirements. In this article, an energy efficient routing protocol, context-aware clustering hierarchy (CACH), is proposed where cluster formation is based on the context of the environment. Moreover, a technique is utilized to avoid similar data traffic across the network. The performance in the simulation shows energy saving which ensures prolonged service life. Copyright 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source]


    Dynamic power management in new architecture of wireless sensor networks

    INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 6 2009
    Chuan Lin
    Abstract Dynamic power management (DPM) technology has been widely used in sensor networks. Though many specific technical challenges remain and deserve much further study, the primary factor currently limiting progress in sensor networks is not these challenges but is instead the lack of an overall sensor network architecture. In this paper, we first develop a new architecture of sensor networks. Then we modify the sleep state policy developed by Sinha and Chandrakasan in (IEEE Design Test Comput. 2001; 18(2):62,74) and deduce that a new threshold satisfies the sleep-state transition policy. Under this new architecture, nodes in deeper sleep states consume lower energy while asleep, but require longer delays and higher latency costs to awaken. Implementing DPM with considering the battery status and probability of event generation will reduce the energy consumption and prolong the whole lifetime of the sensor networks. We also propose a new energy-efficient DPM, which is a modified sleep state policy and combined with optimal geographical density control (OGDC) (Wireless Ad Hoc Sensor Networks 2005; 1(1,2):89,123) to keep a minimal number of sensor nodes in the active mode in wireless sensor networks. Implementing dynamic power management with considering the battery status, probability of event generation and OGDC will reduce the energy consumption and prolong the whole lifetime of the sensor networks. Copyright 2008 John Wiley & Sons, Ltd. [source]


    Coverage area management for wireless sensor networks

    INTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 1 2007
    Isabela G. Siqueira
    In this work, we present a self-management service for Wireless Sensor Networks (WSNs) that automatically controls the network redundancy. Based on a density control function, this service improves the monitoring potential of the sensor nodes. Our simulation experiments show that this self-management service provides good and lasting coverage, as desired by WSNs applications. Copyright 2006 John Wiley & Sons, Ltd. [source]


    Sensor network design for fault tolerant estimation

    INTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 1 2004
    M. Staroswiecki
    Abstract This paper addresses the problem of fault tolerant estimation and the design of fault tolerant sensor networks. Fault tolerance is defined with respect to a given estimation objective, namely a given functional of the system state should remain observable when sensor failures occur. Redundant and minimal sensor sets are defined and organized into an automaton which contains all the subsets of sensors such that the estimation objective can be achieved. Three criteria, which evaluate the system fault tolerance with respect to sensor failures when a reconfiguration strategy is used, are introduced: (strong and weak) redundancy degrees (RD), sensor network reliability (R), and mean time to non-observability (MTTNO). Sensor networks are designed by finding redundant sensor sets whose RD and/or R and/or MTTNO are larger than some specified values. A ship boiler example is developed for illustration. Copyright 2004 John Wiley & Sons, Ltd. [source]


    Network and service architecture for emerging services based on home sensor networks

    BELL LABS TECHNICAL JOURNAL, Issue 2 2009
    Harish Viswanathan
    Sensor networks in the home can enable a variety of applications such as home monitoring and control, home security, home energy management, and home health care. Current state-of-the-art solutions typically target a single sensor application and do not take advantage of the established infrastructure of the broadband service provider, such as a telco operator or cable provider. In this paper, we propose an alternative solution that provides a comprehensive and scalable service platform for multiple parallel home sensor applications, even from third party providers. We highlight the advantages that a broadband service provider holds for providing these emerging high margin services, and derive a suitable end-to-end network architecture. We describe the functions of each of the main components and some of their interfaces, and pay particular attention to one of the key technological challenges: the commissioning and management of the home sensor network. In particular, we describe a laboratory implementation that demonstrates the feasibility of automatic commissioning and remote management of the sensor network. 2009 Alcatel-Lucent. [source]


    Mobile Agent Computing Paradigm for Building a Flexible Structural Health Monitoring Sensor Network

    COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 7 2010
    Bo Chen
    While sensor network approach is a feasible solution for structural health monitoring, the design of wireless sensor networks presents a number of challenges, such as adaptability and the limited communication bandwidth. To address these challenges, we explore the mobile agent approach to enhance the flexibility and reduce raw data transmission in wireless structural health monitoring sensor networks. An integrated wireless sensor network consisting of a mobile agent-based network middleware and distributed high computational power sensor nodes is developed. These embedded computer-based high computational power sensor nodes include Linux operating system, integrate with open source numerical libraries, and connect to multimodality sensors to support both active and passive sensing. The mobile agent middleware is built on a mobile agent system called Mobile-C. The mobile agent middleware allows a sensor network moving computational programs to the data source. With mobile agent middleware, a sensor network is able to adopt newly developed diagnosis algorithms and make adjustment in response to operational or task changes. The presented mobile agent approach has been validated for structural damage diagnosis using a scaled steel bridge. [source]


    DS/CDMA throughput of a multi-hop sensor network in a Rayleigh fading underwater acoustic channel

    CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 8 2007
    Choong Hock Mar
    Abstract Asynchronous half-duplex Direct-Sequence Code-Division Multiple-Access (DS/CDMA) is a suitable candidate for the MAC protocol design of underwater acoustic (UWA) sensor networks owing to its many attractive features. Our ad-hoc multi-hop network is infrastructureless in that it is without centralized base stations or power control. Hence, we develop an asynchronous distributed half-duplex control protocol to regulate between the transmitting and receiving phases of transmissions. Furthermore, multi-hop communications are very sensitive to the time variability of the received signal strength in the fading channel and the ambient noise dominated by snapping shrimp in harsh underwater environments, because a broken link in the multi-hop path is enough to disrupt communications and initiate new route searches. In our configuration, we use the Ad hoc On-demand Distance Vector (AODV) routing protocol optimized for UWA networks. Empirical studies show that we can model the channel as a slow-varying frequency non-selective Rayleigh fading channel. We theoretically analyze the throughput of our configuration by considering three salient features: the ability of the receiver to demodulate the data, the effect of our control protocol and the effect of disconnections on the generation of routing packets. The throughput under various operating conditions is then examined. It is observed that at optimal node separation, the throughput is improved by a factor of 10. Copyright 2007 John Wiley & Sons, Ltd. [source]


    Trust management in wireless sensor networks

    EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 4 2010
    Theodore Zahariadis
    The range of applications of wireless sensor networks is so wide that it tends to invade our every day life. In the future, a sensor network will survey our health, our home, the roads we follow, the office or the industry we work in or even the aircrafts we use, in an attempt to enhance our safety. However, the wireless sensor networks themselves are prone to security attacks. The list of security attacks, although already very long, continues to augment impeding the expansion of these networks. The trust management schemes consist of a powerful tool for the detection of unexpected node behaviours (either faulty or malicious). Once misbehaving nodes are detected, their neighbours can use this information to avoid cooperating with them, either for data forwarding, data aggregation or any other cooperative function. A variety of trust models which follow different directions regarding the distribution of measurement functionality, the monitored behaviours and the way measurements are used to calculate/define the node's trustworthiness has been presented in the literature. In this paper, we survey trust models in an attempt to explore the interplay among the implementation requirements, the resource consumption and the achieved security. Our goal is to draw guidelines for the design of deployable trust model designs with respect to the available node and network capabilities and application peculiarities. Copyright 2010 John Wiley & Sons, Ltd. [source]


    The long-term average capacity region per unit cost with application to protocols for sensor networks

    EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 1 2003
    Daniela Tuninetti
    We consider a wireless sensor network where K sensors must deliver their messages within a frame of N time slots by spending a given finite energy. If the messages are not transmitted within the required delay they become useless and the residual energy is wasted. The channel is block-fading, with independent fades for each sensor and each slot. Sensors know the fading levels up to the current slot, but do not know the future fading levels. The receiver collects the signal on all the slots of the frame and performs joint decoding of all the messages. We characterize the region of long-term average achievable rates and we show that the optimal policy tends to waterfilling in time (optimal policy without delay constraints) as N increases. In this setting, we also characterize the long-term average capacity region per unit energy by showing that the optimal policy is ,one-shot', totally decentralized and extremely simple, i.e., every user spends all its available energy on the first slot of the frame, the fading gain of which is larger than a pre-computed time-varying threshold. Furthermore, the ,one-shot' policy not only makes the most efficient use of the energy, but also reduces to the minimum the interference to other users as it makes all the users transmit with the minimum energy per bit required for reliable communications. These characteristics make the ,one-shot' policy appealing for systems with severe energy limitation as wireless sensor networks. Copyright 2003 AEI [source]


    Energy-efficient target detection in sensor networks using line proxies

    INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 3 2008
    Jangwon Lee
    Abstract One of the fundamental and important operations in sensor networks is sink,source matching, i.e. target detection. Target detection is about how a sink finds the location of source nodes observing the event of interest (i.e. target activity). This operation is very important in many sensor network applications such as military battlefield and environment habitats. The mobility of both targets and sinks brings significant challenge to target detection in sensor networks. Most existing approaches are either energy inefficient or lack of fault tolerance in the environment of mobile targets and mobile sinks. Motivated by these, we propose an energy-efficient line proxy target detection (LPTD) approach in this paper. The basic idea of LPTD is to use designated line proxies as rendezvous points (or agents) to coordinate mobile sinks and mobile targets. Instead of having rendezvous nodes for each target type as used by most existing approaches, we adopt the temporal-based hash function to determine the line in the given time. Then the lines are alternated over time in the entire sensor network. This simple temporal-based line rotation idea allows all sensor nodes in the network to serve as rendezvous points and achieves overall load balancing. Furthermore, instead of network-wide flooding, interests from sinks will be flooded only to designated line proxies within limited area. The interest flooding can further decrease if the interest has geographical constraints. We have conducted extensive analysis and simulations to evaluate the performance of our proposed approach. Our results show that the proposed approach can significantly reduce overall energy consumption and target detection delay. Copyright 2007 John Wiley & Sons, Ltd. [source]


    WHOMoVeS: An optimized broadband sensor network for military vehicle tracking

    INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 3 2008
    Mohamed Hamdi
    Abstract With the advance of sensing technologies and their applications, advanced sensor networks are gaining increasing interest. For certain sensitive applications, heterogeneous sensors can be deployed in the monitored space to ensure scalability, high-speed communication, and long network lifetime. Hybrid sensor networks have capabilities to combine the use of both resource-rich and resource-impoverished sensor nodes. This paper proposes a heterogeneous broadband sensor network architecture for military vehicle tracking. Powerful sensor devices with good bandwidth and energy capabilities are used as a communication backbone while energy sensors are used to track moving targets. Copyright 2007 John Wiley & Sons, Ltd. [source]


    Deployment algorithms for a power-constrained mobile sensor network

    INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 7 2010
    Andrew Kwok
    Abstract This paper presents distributed coverage algorithms for mobile sensor networks in which agents have limited power to move. Rather than making use of a constrained optimization technique, our approach accounts for power constraints by assigning non-homogeneously time-varying regions to each robot. This leads to novel partitions of the environment into limited-range, generalized Voronoi regions. The motion control algorithms are then designed to ascend the gradient of several types of locational optimization functions. In particular, the objective functions reflect the global energy available to the group and different coverage criteria. As we discuss in the paper, this has an effect on limiting each agent's velocity to save energy and balance its expenditure across the network. Copyright 2009 John Wiley & Sons, Ltd. [source]


    A reliable cooperative and distributed management for wireless industrial monitoring and control

    INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 2 2010
    Dr S. Manfredi
    Abstract This paper is concerned with the analysis, design and validation of a reliable management strategy for industrial monitoring and control over wireless sensor network (WSN). First, we investigate the interactions between contention resolution and congestion control mechanisms in Wireless Industrial Sensor Network (briefly WISN). An extensive set of simulations are performed in order to quantify the impacts of several network parameters (i.e. buffer, sensors reporting rate) on the overall network performance (i.e. reliability, packet losses). This calls for cross-layer mechanisms for efficient data delivery over WISN. Second, a reliable sink resource allocation strategy based on log-utility fairness criteria is proposed. It is shown that the resource sink manager can plan strategies to better allocate the available resource among competing sensors. Finally, the analysis, design and validation of a reliable sinks cooperative control for WISN are introduced. A sufficient condition for wireless network stability in presence of multiple sinks and heterogeneous sensors with different time delays is given and it is used for network parameters design. The stability condition and the resulting cooperative control performance in terms of fairness, link utilization, packet losses, reliability and latency are validated by Matlab/Simulink-based simulator TrueTime, which facilitates co-simulation of controller task execution in real-time kernels and in the wireless network environment. Copyright 2009 John Wiley & Sons, Ltd. [source]


    Experience with Delay-Tolerant Networking from orbit,

    INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 5-6 2010
    W. Ivancic
    Abstract We describe the first use from space of the Bundle Protocol for Delay-Tolerant Networking (DTN) and lessons learned from experiments made and experience gained with this protocol. The Disaster Monitoring Constellation (DMC), constructed by Surrey Satellite Technology Ltd (SSTL), is a multiple-satellite Earth-imaging low-Earth-orbit sensor network in which recorded image swaths are stored onboard each satellite and later downloaded from the satellite payloads to a ground station. Store-and-forward of images with capture and later download gives each satellite the characteristics of a node in a disruption-tolerant network. Originally developed for the ,Interplanetary Internet,' DTNs are now under investigation in an Internet Research Task Force (IRTF) DTN research group (RG), which has developed a ,bundle' architecture and protocol. The DMC is technically advanced in its adoption of the Internet Protocol (IP) for its imaging payloads and for satellite command and control, based around reuse of commercial networking and link protocols. These satellites' use of IP has enabled earlier experiments with the Cisco router in Low Earth Orbit (CLEO) onboard the constellation's UK-DMC satellite. Earth images are downloaded from the satellites using a custom IP-based high-speed transfer protocol developed by SSTL, Saratoga, which tolerates unusual link environments. Saratoga has been documented in the Internet Engineering Task Force (IETF) for wider adoption. We experiment with the use of DTNRG bundle concepts onboard the UK-DMC satellite, by examining how Saratoga can be used as a DTN ,convergence layer' to carry the DTNRG Bundle Protocol, so that sensor images can be delivered to ground stations and beyond as bundles. Our practical experience with the first successful use of the DTNRG Bundle Protocol in a space environment gives us insights into the design of the Bundle Protocol and enables us to identify issues that must be addressed before wider deployment of the Bundle Protocol. Published in 2010 by John Wiley & Sons, Ltd. [source]


    Shared environment representation for a human-robot team performing information fusion

    JOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 11-12 2007
    Tobias Kaupp
    This paper addresses the problem of building a shared environment representation by a human-robot team. Rich environment models are required in real applications for both autonomous operation of robots and to support human decision-making. Two probabilistic models are used to describe outdoor environment features such as trees: geometric (position in the world) and visual. The visual representation is used to improve data association and to classify features. Both models are able to incorporate observations from robotic platforms and human operators. Physically, humans and robots form a heterogeneous sensor network. In our experiments, the human-robot team consists of an unmanned air vehicle, a ground vehicle, and two human operators. They are deployed for an information gathering task and perform information fusion cooperatively. All aspects of the system including the fusion algorithms are fully decentralized. Experimental results are presented in form of the acquired multi-attribute feature map, information exchange patterns demonstrating human-robot information fusion, and quantitative model evaluation. Learned lessons from deploying the system in the field are also presented. 2007 Wiley Periodicals, Inc. [source]


    Formation of a geometric pattern with a mobile wireless sensor network

    JOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 10 2004
    Justin Lee
    Mobile wireless sensor networks (MWSNs) will enable information systems to gather detailed information about the environment on an unprecedented scale. These self-organizing, distributed networks of sensors, processors, and actuators that are capable of movement have a broad range of potential applications, including military reconnaissance, surveillance, planetary exploration, and geophysical mapping. In many of the foreseen applications, the MWSN will need to form a geometric pattern without assistance from the user. In military reconnaissance, for example, the nodes will be dropped onto the battlefield from a plane and land at random positions. The nodes will be expected to arrange themselves into a predetermined formation in order to perform a specific task. Thus, we present algorithms for forming a line, circle, and regular polygon from a given set of random positions. The algorithms are distributed and use no communication between the nodes to minimize energy consumption. Unlike past studies of geometric problems where algorithms are either tested in simulations where each node has global knowledge of all the other nodes or implemented on a small number of robots, the robustness of our algorithms has been studied with simulations that model the sensor system in detail. The simulations demonstrate that the algorithms are robust against random errors in the sensors and actuators. 2004 Wiley Periodicals, Inc. [source]


    A flexible RF transmitter module based on flexible printed circuit board by using micro-machining fabrication process

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2010
    Seong-Sik Myoung
    Abstract This article presents a flexible RF transmitter module based on flexible printed circuit board (FPCB). The polyimide with micro-machining fabrication technique is employed for realization of FPCB to achieve the high flexibility as well as low loss at microwave frequency band. The active devices in the proposed flexible RF transmitter are design with InGaP/GaAs hetero-junction bipolar transistor monolithic microwave integrated circuit process, and the passive devices such as the filter and interconnection lines are fully integrated on the FPCB board to avoid use of external off-chip components for maximized flexibility. The FPCB transmitter module is designed for a short-distance sensor network based on OFDM communication system, and the measured conversion gain and error vector magnitude of the fabricated flexible transmitter are 27 dB and ,32 dB, respectively. 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2636,2639, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25572 [source]


    Fiber Bragg grating sensor network based on code division multiple access using a reflective semiconductor optical amplifier

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2010
    Jongkyung Ko
    Abstract We propose a multiplexed fiber Bragg grating sensor network based on code division multiple access (CDMA) using a self-injection locked reflective semiconductor optical amplifier. The proposed system shows improved scanning time without requiring a tunable laser source or a Fabry-Perot filter. CDMA was used to separate each reflected sensor signal and it shows a high dynamic range of over 40C and a crosstalk ratio of 27.7:1. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 378,381, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24913 [source]


    Distributed intelligence in an astronomical Distributed Sensor Network

    ASTRONOMISCHE NACHRICHTEN, Issue 3 2008
    R.R. White
    Abstract The Telescope Alert Operations Network System (TALONS) was designed and developed in the year 2000, around the architectural principles of a distributed sensor network. This network supported the original Rapid Telescopes for Optical Response (RAPTOR) project goals; however, only with further development could TALONS meet the goals of the larger Thinking Telescope Project. The complex objectives of the Thinking Telescope project required a paradigm shift in the software architecture , the centralised intelligence merged into the TALONS network operations could no longer meet all of the new requirements. The intelligence needed to be divorced from the network operations and developed as a series of peripheral intelligent agents, distributing the decision making and analytical processes based on the temporal volatility of the data. This paper is presented as only one part of the poster from the workshop and in it we will explore the details of this architecture and how that merges with the current Thinking Telescope system to meet our project goals. ( 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Network and service architecture for emerging services based on home sensor networks

    BELL LABS TECHNICAL JOURNAL, Issue 2 2009
    Harish Viswanathan
    Sensor networks in the home can enable a variety of applications such as home monitoring and control, home security, home energy management, and home health care. Current state-of-the-art solutions typically target a single sensor application and do not take advantage of the established infrastructure of the broadband service provider, such as a telco operator or cable provider. In this paper, we propose an alternative solution that provides a comprehensive and scalable service platform for multiple parallel home sensor applications, even from third party providers. We highlight the advantages that a broadband service provider holds for providing these emerging high margin services, and derive a suitable end-to-end network architecture. We describe the functions of each of the main components and some of their interfaces, and pay particular attention to one of the key technological challenges: the commissioning and management of the home sensor network. In particular, we describe a laboratory implementation that demonstrates the feasibility of automatic commissioning and remote management of the sensor network. 2009 Alcatel-Lucent. [source]


    Exploiting Context-Awareness in Cluster-Based Wireless Sensor Networks

    IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 5 2009
    Md Enamul Haque Non-member
    Abstract Most of the wireless sensor network's (WSN's) applications require getting accurate information as well as uninterrupted, prolonged service life. Among the constituting elements of WSN, an efficient routing protocol plays a significant role in attaining such service requirements. In this article, an energy efficient routing protocol, context-aware clustering hierarchy (CACH), is proposed where cluster formation is based on the context of the environment. Moreover, a technique is utilized to avoid similar data traffic across the network. The performance in the simulation shows energy saving which ensures prolonged service life. Copyright 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source]


    Mobile Agent Computing Paradigm for Building a Flexible Structural Health Monitoring Sensor Network

    COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 7 2010
    Bo Chen
    While sensor network approach is a feasible solution for structural health monitoring, the design of wireless sensor networks presents a number of challenges, such as adaptability and the limited communication bandwidth. To address these challenges, we explore the mobile agent approach to enhance the flexibility and reduce raw data transmission in wireless structural health monitoring sensor networks. An integrated wireless sensor network consisting of a mobile agent-based network middleware and distributed high computational power sensor nodes is developed. These embedded computer-based high computational power sensor nodes include Linux operating system, integrate with open source numerical libraries, and connect to multimodality sensors to support both active and passive sensing. The mobile agent middleware is built on a mobile agent system called Mobile-C. The mobile agent middleware allows a sensor network moving computational programs to the data source. With mobile agent middleware, a sensor network is able to adopt newly developed diagnosis algorithms and make adjustment in response to operational or task changes. The presented mobile agent approach has been validated for structural damage diagnosis using a scaled steel bridge. [source]


    Effect of redundancy on the mean time to failure of wireless sensor networks

    CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 8 2007
    Anh Phan Speer
    Abstract In data-driven wireless sensor networks (WSNs), the system must perform data sensing and retrieval and possibly aggregate data as a response at runtime. As a WSN is often deployed unattended in areas where replacements of failed sensors are difficult, energy conservation is of primary concern. While the use of redundancy is desirable in terms of satisfying user queries to cope with sensor and transmission faults, it may adversely shorten the lifetime of the WSN, as more sensor nodes will have to be used to answer queries, causing the energy of the system to drain quickly. In this paper, we analyze the effect of redundancy on the mean time to failure (MTTF) of a WSN in terms of the number of queries the system is able to answer correctly before it fails due to either sensor/transmission faults or energy depletion. In particular, we analyze the effect of redundancy on the MTTF of cluster-structured WSNs for energy conservations. We show that a tradeoff exists between redundancy and MTTF. Furthermore, an optimal redundancy level exists such that the MTTF of the system is maximized. Copyright 2007 John Wiley & Sons, Ltd. [source]


    DS/CDMA throughput of a multi-hop sensor network in a Rayleigh fading underwater acoustic channel

    CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 8 2007
    Choong Hock Mar
    Abstract Asynchronous half-duplex Direct-Sequence Code-Division Multiple-Access (DS/CDMA) is a suitable candidate for the MAC protocol design of underwater acoustic (UWA) sensor networks owing to its many attractive features. Our ad-hoc multi-hop network is infrastructureless in that it is without centralized base stations or power control. Hence, we develop an asynchronous distributed half-duplex control protocol to regulate between the transmitting and receiving phases of transmissions. Furthermore, multi-hop communications are very sensitive to the time variability of the received signal strength in the fading channel and the ambient noise dominated by snapping shrimp in harsh underwater environments, because a broken link in the multi-hop path is enough to disrupt communications and initiate new route searches. In our configuration, we use the Ad hoc On-demand Distance Vector (AODV) routing protocol optimized for UWA networks. Empirical studies show that we can model the channel as a slow-varying frequency non-selective Rayleigh fading channel. We theoretically analyze the throughput of our configuration by considering three salient features: the ability of the receiver to demodulate the data, the effect of our control protocol and the effect of disconnections on the generation of routing packets. The throughput under various operating conditions is then examined. It is observed that at optimal node separation, the throughput is improved by a factor of 10. Copyright 2007 John Wiley & Sons, Ltd. [source]


    Trust management in wireless sensor networks

    EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 4 2010
    Theodore Zahariadis
    The range of applications of wireless sensor networks is so wide that it tends to invade our every day life. In the future, a sensor network will survey our health, our home, the roads we follow, the office or the industry we work in or even the aircrafts we use, in an attempt to enhance our safety. However, the wireless sensor networks themselves are prone to security attacks. The list of security attacks, although already very long, continues to augment impeding the expansion of these networks. The trust management schemes consist of a powerful tool for the detection of unexpected node behaviours (either faulty or malicious). Once misbehaving nodes are detected, their neighbours can use this information to avoid cooperating with them, either for data forwarding, data aggregation or any other cooperative function. A variety of trust models which follow different directions regarding the distribution of measurement functionality, the monitored behaviours and the way measurements are used to calculate/define the node's trustworthiness has been presented in the literature. In this paper, we survey trust models in an attempt to explore the interplay among the implementation requirements, the resource consumption and the achieved security. Our goal is to draw guidelines for the design of deployable trust model designs with respect to the available node and network capabilities and application peculiarities. Copyright 2010 John Wiley & Sons, Ltd. [source]


    The long-term average capacity region per unit cost with application to protocols for sensor networks

    EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 1 2003
    Daniela Tuninetti
    We consider a wireless sensor network where K sensors must deliver their messages within a frame of N time slots by spending a given finite energy. If the messages are not transmitted within the required delay they become useless and the residual energy is wasted. The channel is block-fading, with independent fades for each sensor and each slot. Sensors know the fading levels up to the current slot, but do not know the future fading levels. The receiver collects the signal on all the slots of the frame and performs joint decoding of all the messages. We characterize the region of long-term average achievable rates and we show that the optimal policy tends to waterfilling in time (optimal policy without delay constraints) as N increases. In this setting, we also characterize the long-term average capacity region per unit energy by showing that the optimal policy is ,one-shot', totally decentralized and extremely simple, i.e., every user spends all its available energy on the first slot of the frame, the fading gain of which is larger than a pre-computed time-varying threshold. Furthermore, the ,one-shot' policy not only makes the most efficient use of the energy, but also reduces to the minimum the interference to other users as it makes all the users transmit with the minimum energy per bit required for reliable communications. These characteristics make the ,one-shot' policy appealing for systems with severe energy limitation as wireless sensor networks. Copyright 2003 AEI [source]


    Stretchable, Large-area Organic Electronics

    ADVANCED MATERIALS, Issue 20 2010
    Tsuyoshi Sekitani
    Abstract Stretchability will significantly expand the application scope of electronics, particularly large-area electronics,displays, sensors, and actuators. If arbitrary surfaces and movable parts could be covered with stretchable electronics, which is impossible with conventional electronics, new classes of applications are expected to emerge. A large hurdle is manufacturing electrical wiring with high conductivity, high stretchability, and large-area compatibility. This Review describes stretchable, large-area electronics based on organic field-effect transistors for applications to sensors and displays. First, novel net-shaped organic transistors are employed to realize stretchable, large-area sensor networks that detect distributions of pressure and temperature simultaneously. The whole system is functional even when it is stretched by 25%. In order to further improve stretchability, printable elastic conductors are developed by dispersing single-walled carbon nanotubes (SWNTs) as dopants uniformly in rubbers. Further, we describe integration of printable elastic conductors with organic transistors to construct a rubber-like stretchable active matrix for large-area sensor and display applications. Finally, we will discuss the future prospects of stretchable, large-area electronics with delineating a picture of the next-generation human/machine interfaces from the aspect of materials science and electronic engineering. [source]