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Wireless Sensor Networks (wireless + sensor_network)
Selected AbstractsExploiting Context-Awareness in Cluster-Based Wireless Sensor NetworksIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 5 2009Md 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] Coverage area management for wireless sensor networksINTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 1 2007Isabela 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] An adaptive joining mechanism for improving the connection ratio of ZigBee wireless sensor networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 2 2010Tien-Wen Sung Abstract Wireless sensor networks (WSNs) are well suited to many applications, including environment surveillance and target tracking. ZigBee is an IEEE 802.15.4-based standard that is considered suitable for WSNs. The functional operations of a ZigBee network rely on self-organized network connections and the proper deployment of sensor devices. However, the devices comprising a ZigBee network may become isolated from the network after the joining phase due to the configuration constraints of the ZigBee standard. This means that some deployed devices cannot join the network even though they can communicate with other joined nodes. These isolated devices reduce the efficiency of network operation and increase deployment costs. This paper proposes a ZigBee-compatible adaptive joining mechanism with connection shifting schemes to improve the connectivity of ZigBee networks, allowing them to operate at the expected efficiency. Simulation results show that the proposed mechanism significantly improves the join ratio of deployed sensor devices in ZigBee WSNs. Copyright © 2009 John Wiley & Sons, Ltd. [source] Delay aware reliable transport in wireless sensor networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 10 2007Vehbi C. Gungor Abstract Wireless sensor networks (WSN) are event-based systems that rely on the collective effort of several sensor nodes. Reliable event detection at the sink is based on collective information provided by the sensor nodes and not on any individual sensor data. Hence, conventional end-to-end reliability definitions and solutions are inapplicable in the WSN regime and would only lead to a waste of scarce sensor resources. Moreover, the reliability objective of WSN must be achieved within a certain real-time delay bound posed by the application. Therefore, the WSN paradigm necessitates a collective delay-constrained event-to-sink reliability notion rather than the traditional end-to-end reliability approaches. To the best of our knowledge, there is no transport protocol solution which addresses both reliability and real-time delay bound requirements of WSN simultaneously. In this paper, the delay aware reliable transport (DART) protocol is presented for WSN. The objective of the DART protocol is to timely and reliably transport event features from the sensor field to the sink with minimum energy consumption. In this regard, the DART protocol simultaneously addresses congestion control and timely event transport reliability objectives in WSN. In addition to its efficient congestion detection and control algorithms, it incorporates the time critical event first (TCEF) scheduling mechanism to meet the application-specific delay bounds at the sink node. Importantly, the algorithms of the DART protocol mainly run on resource rich sink node, with minimal functionality required at resource constrained sensor nodes. Furthermore, the DART protocol can accommodate multiple concurrent event occurrences in a wireless sensor field. Performance evaluation via simulation experiments show that the DART protocol achieves high performance in terms of real-time communication requirements, reliable event detection and energy consumption in WSN. Copyright © 2007 John Wiley & Sons, Ltd. [source] The long-term average capacity region per unit cost with application to protocols for sensor networksEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 1 2003Daniela 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] A reliable cooperative and distributed management for wireless industrial monitoring and controlINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 2 2010Dr 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] Formation of a geometric pattern with a mobile wireless sensor networkJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 10 2004Justin 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] Exploiting Context-Awareness in Cluster-Based Wireless Sensor NetworksIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 5 2009Md 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] Effect of redundancy on the mean time to failure of wireless sensor networksCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 8 2007Anh 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] Trust management in wireless sensor networksEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 4 2010Theodore 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 networksEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 1 2003Daniela 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] Error resilient data transport in sensor network applications: A generic perspective,INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 2 2009Rachit Agarwal Abstract The error recovery problem in wireless sensor networks is studied from a generic resource-constrained energy-optimization perspective. To characterize the features of error recovery schemes that suit the majority of applications, an energy model is developed and inferences are drawn based on a suitable performance metric. For applications that require error control coding, an efficient scheme is proposed based on an interesting observation related to shortened Reed,Solomon (RS) codes for packet reliability. It is shown that multiple instances (,) of RS codes defined on a smaller alphabet combined with interleaving results in smaller resource usage, while the performance exceeds the benefits of a shortened RS code defined over a larger alphabet. In particular, the proposed scheme can have an error correction capability of up to , times larger than that of the conventional RS scheme without changing the rate of the code with much lower power, timing and memory requirements. Implementation results show that such a scheme is 43% more power efficient compared with the RS scheme with the same code rate. Besides, such an approach results in 46% faster computations and 53% reduction in memory requirements. Copyright © 2008 John Wiley & Sons, Ltd. [source] An adaptive joining mechanism for improving the connection ratio of ZigBee wireless sensor networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 2 2010Tien-Wen Sung Abstract Wireless sensor networks (WSNs) are well suited to many applications, including environment surveillance and target tracking. ZigBee is an IEEE 802.15.4-based standard that is considered suitable for WSNs. The functional operations of a ZigBee network rely on self-organized network connections and the proper deployment of sensor devices. However, the devices comprising a ZigBee network may become isolated from the network after the joining phase due to the configuration constraints of the ZigBee standard. This means that some deployed devices cannot join the network even though they can communicate with other joined nodes. These isolated devices reduce the efficiency of network operation and increase deployment costs. This paper proposes a ZigBee-compatible adaptive joining mechanism with connection shifting schemes to improve the connectivity of ZigBee networks, allowing them to operate at the expected efficiency. Simulation results show that the proposed mechanism significantly improves the join ratio of deployed sensor devices in ZigBee WSNs. Copyright © 2009 John Wiley & Sons, Ltd. [source] Dynamic power management in new architecture of wireless sensor networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 6 2009Chuan 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] Delay aware reliable transport in wireless sensor networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 10 2007Vehbi C. Gungor Abstract Wireless sensor networks (WSN) are event-based systems that rely on the collective effort of several sensor nodes. Reliable event detection at the sink is based on collective information provided by the sensor nodes and not on any individual sensor data. Hence, conventional end-to-end reliability definitions and solutions are inapplicable in the WSN regime and would only lead to a waste of scarce sensor resources. Moreover, the reliability objective of WSN must be achieved within a certain real-time delay bound posed by the application. Therefore, the WSN paradigm necessitates a collective delay-constrained event-to-sink reliability notion rather than the traditional end-to-end reliability approaches. To the best of our knowledge, there is no transport protocol solution which addresses both reliability and real-time delay bound requirements of WSN simultaneously. In this paper, the delay aware reliable transport (DART) protocol is presented for WSN. The objective of the DART protocol is to timely and reliably transport event features from the sensor field to the sink with minimum energy consumption. In this regard, the DART protocol simultaneously addresses congestion control and timely event transport reliability objectives in WSN. In addition to its efficient congestion detection and control algorithms, it incorporates the time critical event first (TCEF) scheduling mechanism to meet the application-specific delay bounds at the sink node. Importantly, the algorithms of the DART protocol mainly run on resource rich sink node, with minimal functionality required at resource constrained sensor nodes. Furthermore, the DART protocol can accommodate multiple concurrent event occurrences in a wireless sensor field. Performance evaluation via simulation experiments show that the DART protocol achieves high performance in terms of real-time communication requirements, reliable event detection and energy consumption in WSN. Copyright © 2007 John Wiley & Sons, Ltd. [source] An energy-efficient multipath routing protocol for wireless sensor networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 7 2007Ye Ming Lu Abstract The energy consumption is a key design criterion for the routing protocols in wireless sensor networks. Some of the conventional single path routing schemes may not be optimal to maximize the network lifetime and connectivity. In this paper, we propose a distributed, scalable and localized multipath search protocol to discover multiple node-disjoint paths between the sink and source nodes. We also propose a load balancing algorithm to distribute the traffic over the multiple paths discovered. We compare our proposed scheme with the directed diffusion, directed transmission, N -to-1 multipath routing, and the energy-aware routing protocols. Simulation results show that our proposed scheme has a higher node energy efficiency, lower average delay and control overhead than those protocols. Copyright © 2006 John Wiley & Sons, Ltd. [source] Efficient Delaunay-based localized routing for wireless sensor networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 7 2007Yu Wang Abstract Consider a wireless sensor network consisting of n wireless sensors randomly distributed in a two-dimensional plane. In this paper, we show that with high probability we can locally find a path for any pair of sensors such that the length of the path is no more than a constant factor of the minimum. By assuming each sensor knows its position, our new routing method decides where to forward the message purely based on the position of current node, its neighbours, and the positions of the source and the target. Our method is based on a novel structure called localized Delaunay triangulation and a geometric routing method that guarantees that the distance travelled by the packets is no more than a small constant factor of the minimum when the Delaunay triangulation of sensor nodes are known. Our experiments show that the delivery rates of existing localized routing protocols are increased when localized Delaunay triangulation is used instead of several previously proposed topologies, and our localized routing protocol based on Delaunay triangulation works well in practice. We also conducted extensive simulations of another localized routing protocol, face routing. The path found by this protocol is also reasonably good compared with previous one although it cannot guarantee a constant approximation on the length of the path travelled theoretically. Copyright © 2006 John Wiley & Sons, Ltd. [source] Coverage area management for wireless sensor networksINTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 1 2007Isabela 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] Network management in new realms: wireless sensor networksINTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 4 2005Athanassios Boulis No abstract is available for this article. [source] Formation of a geometric pattern with a mobile wireless sensor networkJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 10 2004Justin 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] Frequency-detected acoustic ranging solutions in wireless sensor networks: an experimental studyASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 6 2008Jiming Chen Abstract Ranging is a basic distance estimation for many range-based localization approaches, which are important to wireless sensor networks (WSNs) applications at many levels. In this paper, we propose a simple frequency-detected based time difference of arrival (FD-TDoA), which can be implemented by detecting acoustic frequency to compute the time of flight in air. Furthermore, we put forward a new acoustic ranging solution named time of arrival (TOA)2, which can be applied to WSNs with asynchronous nodes. Unlike other published works, the design of TOA2 uses a bidirectional acoustic signal exchange between a pair of communication nodes. This technique is significantly simple and effective. The latency between the time at which the Mica2 is commanded to emit an acoustic pulse and the earliest possible time that can be detected anywhere, is considered in our solutions. The error of these ranging solutions, the correction expressions by fitted lines and the sensitivity on hardware are analyzed by a large number of experiments based on a resource-constrained Mica2 hardware platform. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd. [source] | |||||||||||||||||||||||||