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5th acm conference on embedded networked sensor systems

作者： Kusy, Branislav Ledeczi, Akos Koutsoukos, Xenofon Vanderbilt Univ Nashville TN 37203 USA

ISBN: (纸本)9781595937636

In this paper, we address the problem of tracking cooperative mobile nodes in wireless sensor networks. Aiming at a resource efficient solution, we advocate the use of sensors that maintain their location information and rely oil the tracking service only when their locations change. In the proposed approach, the tracked node transmits a signal and infrastructure nodes measure the Doppler shifts of the transmitted signal. We show that Mica2 motes can measure RF- Doppler shifts with 0.2 Hz accuracy corresponding to a 0.14 m/s error in relative speed estimates using radio interferometric technique. the tracking problem is modeled as a non-linear optimization problem and an extended Kalman filter is used to solve it accurately assuming Gaussian measurement errors. However, this approach may fail if the tracked node changes its speed or direction. We propose to update the Kalman filter state by performing constrained least-squares optimization when a maneuver is detected. the combined approach achieves almost a 50% accuracy improvement over the Kalman filter alone when the mobile node changes its direction and speed frequently. We describe our proof-of-concept implementation of the tracking service and evaluate its performance experimentally and ill simulation.

关键词： sensor Networks Doppler effect Tracking

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MSP: Multi-Sequence Positioning of Wireless sensor Nodes 07

MSP: Multi-Sequence Positioning of Wireless Sensor Nodes

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5th acm conference on embedded networked sensor systems

作者： Zhong, Ziguo He, Tian Univ Minnesota Minneapolis MN 55455 USA

ISBN: (纸本)9781595937636

Wireless sensor Networks have been proposed for use in many location-dependent applications. Most of these need to identify the locations of wireless sensor nodes, a challenging task because of the severe constraints oil cost, energy and effective range of sensor devices. To overcome limitations in existing solutions, we present a Multi-Sequence Positioning (MSP) method for large-scale stationary sensor node localization ill outdoor environments. the novel idea behind MSP is to reconstruct and estimate two-dimensional location information for each sensor node by processing multiple one-dimensional node sequences, easily obtained through loosely guided event distribution. Starting from a basic MSP design, we propose four optimizations, which work together to increase the localization accuracy. We address several interesting issues, such as incomplete (partial) node sequences and sequence flip, found in the Mirage test-bed we built. We have evaluated the MSP system through theoretical analysis, extensive simulation as well as two physical systems (an indoor version with 46 MICAz motes and an outdoor version with 20 MICAz motes). this evaluation demonstrates that MSP call achieve an accuracy within one foot, requiring neither additional costly hardware on sensor nodes nor precise event distribution. It also provides a nice tradeoff between physical cost (anchors) and soft cost (events), while maintaining localization accuracy.

关键词： Wireless sensor Networks Localization Node Sequence Processing

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Demo abstract: Multi-radio medium access control protocol for wireless sensor networks

Demo abstract: Multi-radio medium access control protocol fo...

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5th acm International conference on embedded networked sensor systems, SenSys'07

作者： Ansari, Junaid Zhang, Xi Mähönen, Petri Department of Wireless Networks RWTH Aachen University Kackertstrasse 9 D-52072 Aachen Germany

ISBN: (纸本)9781595937636

In this demonstration paper, we present a multi-radio MAC protocol and a prototype sensor node platform which supports dual frequency bands of operation. the multi-radio MAC protocol combines the advantages of both high and low frequency bands to give an energy efficient performance with high throughput and low latency in several applications. Our prototype supports spectrum agility, which is becoming important due to ever crowding spectrum. Besides demonstrating the improved performance metrics and spectrum agility support, we will also present the flexibility provided by our MAC protocol.

关键词： Medium access control

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Exploring In-Situ Sensing Irregularity in Wireless sensor Networks 07

Exploring In-Situ Sensing Irregularity in Wireless Sensor Ne...

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5th acm conference on embedded networked sensor systems

作者： Hwang, Joengmin He, Tian Kim, Yongdae Univ Minnesota Dept Comp Sci & Engn Minneapolis MN 55455 USA

ISBN: (纸本)9781595937636

the circular sensing model has been widely used to estimate performance of sensing applications in existing analysis and simulations. While this model provides valuable high-level guidelines, the quantitative results obtained may not reflect the true performance of these applications, due to the existence of obstacles and sensing irregularity introduced by insufficient hardware calibration. In this project, we design and implement two Sensing Area Modeling (SAM) techniques useful in the real world. they complement each other in the design space. P-SAM provides accurate sensing area models for individual nodes using controlled or monitored events, while V-SAM provides continuous sensing similarity models using natural events in an environment. With these two models, we pioneer an investigation of the impact of sensing irregularity on application performance, such as coverage scheduling. We evaluate SAM extensively in real-world settings, using three testbeds consisting of 40 MICAz motes and 14 XSM motes. To study the performance at scale, we also provide an extensive 1,400-node simulation. Evaluation results reveal several serious issues concerning circular models, and demonstrate significant improvements

关键词： Model Irregularity Event Sensing Coverage Scheduling Similarity

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Demo abstract: Software-based sensor node energy estimation

Demo abstract: Software-based sensor node energy estimation

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5th acm International conference on embedded networked sensor systems, SenSys'07

作者： Dunkels, Adam Österlind, Fredrik Tsiftes, Nicolas He, Zhitao Swedish Institute of Computer Science Sweden

ISBN: (纸本)9781595937636

Being able to estimate the energy consumption of sensor nodes is essential both for evaluating existing sensor network mechanisms and for constructing new energy-aware mechanisms. We present a software-based mechanism for estimating the energy consumption of sensor node at run-time. Unlike previous energy estimation mechanisms, our mechanism does not require any additional hardware components or add-ons. Our demonstration shows the energy estimation in practice on a small network of Tmote Sky motes running the Contiki operating system. A PC connected to one of the motes shows the real-time energy estimation of the network nodes and where the energy is spent: CPU active, CPU sleeping, radio transmitting, radio listening, and LEDs. Copyright is held by the author/owner(s).

关键词： sensor nodes

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Multi-user Data Sharing in Radar sensor Networks 07

Multi-user Data Sharing in Radar Sensor Networks

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5th acm conference on embedded networked sensor systems

作者： Li, Ming Yan, Tingxin Ganesan, Deepak Lyons, Eric Shenoy, Prashant Venkataramani, Arun Zink, Michael Univ Massachusetts Dept Comp Sci Amherst MA 01003 USA

ISBN: (纸本)9781595937636

In this paper, we focus on a network of rich sensors that are geographically distributed and argue that the design of such networks poses very different challenges front traditional "mote-class" sensor network design. We identify the need to handle the diverse requirements of multiple users to be a major design challenge, and propose a utility-driven approach to maximize data sharing across users while judiciously using limited network and computational resources. Our utility-driven architecture addresses three key challenges for Such rich multi-user sensor networks: how to define utility functions for networks with data sharing among end-users, how to compress and prioritize data transmissions according to its importance to end-users, and how to gracefully degrade end-user utility in the presence of bandwidth fluctuations. We instantiate this architecture in the context of geographically distributed wireless radar sensor networks for weather, and present results from an implementation of our system on a multi-hop wireless mesh network that Uses real radar data with real end-user applications. Our results demonstrate that our progressive compression and transmission approach achieves an Order of magnitude improvement in application utility over existing utility-agnostic non-progressive approaches, while also scaling better with the number of nodes in the network.

关键词： Multi-user sensor Networks Radar sensor Networks Wireless Mesh Networks Utility Control Progressive Encoding

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Eon: A Language and Runtime System for Perpetual systems 07

Eon: A Language and Runtime System for Perpetual Systems

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5th acm conference on embedded networked sensor systems

作者： Sorber, Jacob Kostadinov, Alexander Garber, Matthew Brennan, Matthew Corner, Mark D. Berger, Emery D. Univ Massachusetts Dept Comp Sci Amherst MA 01003 USA

ISBN: (纸本)9781595937636

embedded systems can operate perpetually without being connected to a power source by harvesting environmental energy from motion, the sun, wind, or heat differentials. However, programming these perpetual systems is challenging. In response to changing energy levels, programmers can adjust the execution frequency of energy-intensive tasks, or provide higher service levels when energy is plentiful and lower service levels when energy is scarce. However, it is often difficult for programmers to predict the energy consumption resulting from these adjustments. Worse, explicit energy management can tie a program to a particular hardware platform, limiting portability. this paper introduces Eon, a programming language and runtime system designed to support the development of perpetual systems. To our knowledge, Eon is the first energy-aware programming language. Eon is a declarative coordination language that lets programmers compose programs from components written in C or nesC. Paths through the program ("flows") may be annotated with different energy states. Eon's automatic energy management then dynamically adapts these states to current and predicted energy levels. It chooses flows to execute and adjusts their rates of execution, maximizing the quality of service under available energy constraints. We demonstrate the utility and portability of Eon by deploying two perpetual applications on widely different hardware platforms: a GPS-based location tracking sensor deployed on a threatened species of turtle and on automobiles, and a solar-powered camera sensor for remote,. ad-hoc deployments. We also evaluate the simplicity and effectiveness of Eon with a user study, in which novice Eon programmers produced more efficient efficient energy-adaptive systems in substantially less time than experienced C programmers.

关键词： Coordination Languages Energy Management Energy Harvesting embedded systems

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Range-efficient counting of distinct elements in a massive data stream

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SIAM JOURNAL ON COMPUTING 2007年第2期37卷 359-379页

作者： Pavan, A. Tirthapura, Srikanta Iowa State Univ Dept Comp Sci Ames IA 50010 USA Iowa State Univ Dept Elect & Comp Engn Ames IA 50010 USA

Efficient one-pass estimation of F-0, the number of distinct elements in a data stream, is a fundamental problem arising in various contexts in databases and networking. We consider range-efficient estimation of F0: estimation of the number of distinct elements in a data stream where each element of the stream is not just a single integer but an interval of integers. We present a randomized algorithm which yields an (is an element of, delta)-approximation of F-0, with the following time and space complexities (n is the size of the universe of the items): (1) the amortized processing time per interval is O(log (1)/(delta) log (n)/(is an element of)). (2) the workspace used is O((1)/(is an element of 2) log (1)/(delta) log n) bits. Our algorithm improves upon a previous algorithm by Bar-Yossef, Kumar and Sivakumar [proceedings of the 13th acm - SIAM Symposium on Discrete Algorithms (SODA), 2002, pp. 623 - 632], which requires O((1)/(is an element of 5) log (1)/(delta) log(5) n) processing time per item. this algorithm can also be used to compute the max-dominance norm of a stream of multiple signals and significantly improves upon the previous best time and space bounds by Cormode and Muthukrishnan [proceedings of the 11th European Symposium on Algorithms (ESA), Lecture Notes in Comput. Sci. 2938, Springer, Berlin, 2003, pp. 148 - 160]. this algorithm also provides an efficient solution to the distinct summation problem, which arises during data aggregation in sensor networks [proceedings of the 2nd International conference on embedded networked sensor systems, acm Press, New York, 2004, pp. 250 - 262, proceedings of the 20th International conference on Data Engineering (ICDE), 2004, pp. 449 - 460].

关键词： data streams range efficiency distinct elements reductions sensor networks

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Catching Elephants with Mice: Sparse Sampling for Monitoring sensor Networks 07

Catching Elephants with Mice: Sparse Sampling for Monitoring...

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5th acm conference on embedded networked sensor systems

作者： Gandhi, Sorabh Suri, Subhash Welzl, Emo UC Santa Barbara Dept Comp Sci Santa Barbara CA USA

ISBN: (纸本)9781595937636

We propose a scalably efficient scheme for detecting large-scale physically-correlated events in sensor networks. Specifically, we show that in a network of n sensors arbitrarily distributed in the plane, a sample of 0(1/epsilon log 1/epsilon) sensor e E nodes (mice) is sufficient to catch any, and only those, events that affect Omega(epsilon n) nodes (elephants), for any 0 < epsilon < 1, as long as the geometry of the event has a bounded VapnikChervonenkis (VC) dimension. In fact, the scheme is provably able to estimate the size of all event within the approximation error of +/-epsilon n/4, which call be improved further at the expense of more mice. the detection algorithm itself requires knowledge of the event geometry (e.g. circle, ellipse, or rectangle) for the sake of computational efficiency, but the combinatorial bound on the sample size (set of mice) depends only on the VC dimension of the event class and not the precise shape geometry. While nearly optimal in theory, due to implicit constant factors, these "scale-free" bounds still prove too large in practice if applied blindly. We, therefore, propose heuristic improvements and perform empirical parameter tuning to counter the pessimism inherent in these theoretical estimates. Using a variety of data distributions and event geometries, we show through simulations that the final scheme is eminently scalable and practical for large-scale network, say, with n >= 1000. the overall simplicity and generality of our technique suggests that it may be well-suited for a wide class of sensornet applications, including monitoring of physical environments, network anomalies, network security, or any abstract binary event that affects a significant number of nodes in the network.

关键词： sensor networks monitoring VC-dimension epsilon-nets

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A cross-layer framework design for the embedded middleware in mobility applications (EMMA) project

A cross-layer framework design for the embedded middleware i...

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19th IASTED International conference on Parallel and Distributed Computing and systems

作者： Jambli, Mohamad Nazim Tully, Alan Selvarajah, Kirusnapillai Lachenmann, Andreas School of Computing Science Newcastle University United Kingdom Institute of Parallel and Distributed Systems Universität Stuttgart Germany

ISBN: (纸本)9780889867048

the severe energy constraints of wireless sensor networks (WSNs) require energy-efficient communication protocols in order to fulfill the objectives of the application. Cross-layer design is a technique which can potentially be used to improve the overall performance of WSNs by way of jointly optimizing and exploiting the interactions between various layers of the network protocol stack. In this paper, we propose a cross-layer framework design for the embedded Middleware in Mobility Applications (EMMA) project. this optimization agent based framework design provides efficient data exchange between the various protocols layers via a state repository to improve the performance of WSN applications in terms of memory consumption and processing overhead.

关键词： Wireless sensor networks

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