Showing papers on "Sensor web published in 2005"

MoteLab: a wireless sensor network testbed

Abstract: As wireless sensor networks have emerged as a exciting new area of research in computer science, many of the logistical challenges facing those who wish to develop, deploy, and debug applications on realistic large-scale sensor networks have gone unmet. Manually reprogramming nodes, deploying them into the physical environment, and instrumenting them for data gathering is tedious and time-consuming. To address this need we have developed MoteLab, a Web-based sensor network testbed. MoteLab consists of a set of permanently-deployed sensor network nodes connected to a central server which handles re programming and data logging while providing a Web interface for creating and scheduling jobs on the testbed. MoteLab accelerates application deployment by streamlining access to a large, fixed network of real sensor network devices; it accelerates debugging and development by automating data logging, allowing the performance of sensor network software to be evaluated offline Additionally, by providing a Web interface MoteLab allows both local and remote users access to the testbed, and its scheduling and quota system ensure fair sharing. We have developed and deployed MoteLab at Harvard and found ft invaluable for both research and teaching. The MoteLab source is freely available, easy to install, and already in use at several other research institutions. We expect that widespread use of MoteLab will accelerate and improve wireless sensor network research.

Key distribution mechanisms for wireless sensor networks : a survey

Abstract: Advances in technology introduce new application areas for sensor networks. Foreseeable wide deployment of mission critical sensor networks creates concerns on security issues. Security of large scale densely deployed and infrastructure less wireless networks of resource limited sensor nodes requires efficient key distribution and management mechanisms. We consider distributed and hierarchical wireless sensor networks where unicast, multicast and broadcast type of communications can take place. We evaluate deterministic, probabilistic and hybrid type of key pre-distribution and dynamic key generation algorithms for distributing pair-wise, group-wise and network-wise keys.

Robomote: enabling mobility in sensor networks

Abstract: Severe energy limitations, and a paucity of computation pose a set of difficult design challenges for sensor networks. Recent progress in two seemingly disparate research areas namely, distributed robotics and low power embedded systems has led to the creation of mobile (or robotic) sensor networks. Autonomous node mobility brings with it its own challenges, but also alleviates some of the traditional problems associated with static sensor networks. We illustrate this by presenting the design of the robomote, a robot platform that functions as a single mobile node in a mobile sensor network. We briefly describe two case studies where the robomote has been used for table top experiments with a mobile sensor network.

Overview of Wireless Sensor Networks

Abstract: The invention of ubiquitous computing and increase of portable devices have raised the importance of mobile and wireless networking. Wireless networking is an emerging technology that makes the users to access data and services electronically, irrespective of their geographic location. Wireless network is a data communication system, which uses electromagnetic waves to transmit and receive information via air as medium from one place to another place. Basically wireless networks are classified into two types: infrastructure-based networks and infrastructure-less (ad-hoc) networks. Infrastructure-based networks have fixed BSs called access points which are connected by wires. The mobile nodes communicate with the BS via wireless link when it is inside the communication range of it. When the mobile node moves out of the communication range of a BS, it makes the connection with the other base station for communication. Cellular phone system, wireless local area networks (WLAN), paging systems are some of the example of

TASK: sensor network in a box

Abstract: Sensornet systems research is being conducted with various applications and deployment scenarios in mind. In many of these scenarios, the presumption is that the sensornet will be deployed and managed by users who do not have a background in computer science. In this paper we describe the "tiny application sensor kit" (TASK), a system we have designed for use by end-users with minimal sensornet sophistication. We describe the requirements that guided our design, the architecture of the system and results from initial deployments. Based on our experience to date we present preliminary design principles and research challenges that arise in delivering sensornet research to end users.

Building a Sensor Ontology: A Practical Approach Leveraging ISO and OGC Models.

Abstract: - This paper describes the approach to building OntoSensor: a prototype sensor knowledge repository compatible with evolving Semantic Web infrastructure. OntoSensor includes definitions of concepts and properties adopted in part from SensorML, extensions to IEEE SUMO and references to ISO 19115. Simple queries have been developed and tested using Protege 2000 and Prolog. Although OntoSensor is in the early development stage, it presents a practical approach to building a sensor knowledge repository. It is proposed that OntoSensor may serve as a component in comprehensive applications that include more advanced inference mechanisms. Such comprehensive applications will be used for synergistic fusion of heterogeneous data in a network-centric environment. Keywords: Data Fusion, Semantic Web, Sensor Ontology 1.0 Introduction The assessment of situations and strategies in complex environments requires the fusion of information from heterogeneous data sources including sensors [1]. Synergistic fusion of data from multiple sensors ranging in complexity from simple acoustic sensors to sophisticated imaging equipment such as Forward Looking Infrared (FLIR) sensors will lead to the extraction of knowledge that cannot be perceived or inferred using individual sensors alone. For example, information from diverse sources such as sensors on an Unmanned Aerial Vehicle (UAV), reconnaissance reports and satellite imagery can be integrated to obtain high-level knowledge of objects in an area under surveillance including their spatial and temporal interrelationships; and to generate predictions of their intentions, positions and alignments in future states.

Algorithms for generic role assignment in wireless sensor networks

Abstract: We consider configuration of wireless sensor networks, where certain functions must be automatically assigned to sensor nodes, such that the properties of a sensor node (e.g., remaining energy, network neighbors) match the requirements of the assigned function. Essentially, sensor nodes take on certain roles in the network as a result of configuration. To help developers with such configuration tasks for a variety of applications, we propose generic role assignment as a programming abstraction, where roles and rules for their assignment can be easily specified using a configuration language. We present such a role specification language and distributed algorithms for role assignment according to such specifications. We evaluate our approach and show that efficient and robust generic role assignment is practically feasible for wireless sensor networks.

Realizing Robust User Authentication in Sensor Networks

Abstract: We investigate how to organize access control to the WSN data in such a way that an unauthorized entity (the adversary) cannot make arbitrary queries to the WSN. We call this problem authenticated querying. Roughly, this means that whenever the sensor nodes process a query, they should be able to verify that the query comes from a legitimate user. Authenticated querying is especially challenging if the adversary can gain full control over some sensor nodes through physical access (node capture attack). We propose first solution to this problem and present our experiments with an implementation of the first step of this solution.

A Survey of Solutions for the Coverage Problems in Wireless Sensor Networks

Abstract: Recently, wireless sensor networks have attracted a lot of attention. Such environments may consist of many inexpensive nodes, each capable of collecting, storing, and processing environmental information, and communicating with neighboring nodes through wireless links. In this paper, we survey a fundamental problem in wireless sensor networks, the coverage problem, which reflects how well an area is monitored or tracked by sensors. We first study several relevant computational geometric problems. Then, a number of papers aimed at solving the coverage problem in wireless sensor networks are discussed. We will address issues such as surveillance and exposure of sensor networks, coverage and connectivity in network deployment, and coverage- and energy-preserving protocols for sensor networks.

An Ultra Low Power System Architecture for Sensor Network Applications

Abstract: Recent years have seen a burgeoning interest in embedded wireless sensor networks with applications ranging from habitat monitoring to medical applications. Wireless sensor networks have several important attributes that require special attention to device design. These include the need for inexpensive, long-lasting, highly reliable devices coupled with very low performance requirements. Ultimately, the "holy grail" of this design space is a truly untethered device that operates off of energy scavenged from the ambient environment. In this paper, we describe an application-driven approach to the architectural design and implementation of a wireless sensor device that recognizes the event-driven nature of many sensor-network workloads. We have developed a full-system simulator for our sensor node design to verify and explore our architecture. Our simulation results suggest one to two orders of magnitude reduction in power dissipation over existing commodity-based systems for an important class of sensor network applications. We are currently in the implementation stage of design, and plan to tape out the first version of our system within the next year.

Environmental Sensor Networks

Abstract: This report is based on the 2004 AGU Fall Meeting's session entitled “Special Focus: Advances in Data Acquisition, Management, Analysis and Display: Cyberinfrastructure for Earth Systems Science IV: Sensor Networks.” An environmental sensor network comprises an array of sensors that gather data autonomously and automatically forward the data to a central server. What differentiates modern sensor networks from previous techniques is an emphasis on “intelligence” in the sensor packages as well as the data network. Modern sensor networks also typically publish the data on the server to the World Wide Web and allow real-time access to the data. These networks require a unique combination of technological and environmental understanding, and have the potential of creating a revolution in environmental monitoring, similar in impact to satellite remote sensing in the 1970s.

On the coverage problem in video-based wireless sensor networks

Abstract: Video-based wireless sensor networks continue to gain increasing interest due to their ability to collect visual information for a wide range of applications. However, knowledge about these types of networks is mostly related to visual algorithms, leaving the networking perspective aside. In this work, we analyze how an algorithm designed for traditional wireless sensor networks, which integrates the coverage and routing problem, behaves in video-based networks. Our results show that because of the unique way that cameras capture data, the sensor network algorithm does not give the expected results in terms of coverage preservation of monitored areas. We discuss the main differences between traditional wireless sensor networks and video-based networks that lead to such a result, and we provide ideas for how protocols should be designed for the unique features of video-based networks

Security considerations in ad hoc sensor networks

Abstract: In future smart environments, ad hoc sensor networks will play a key role in sensing, collecting, and disseminating information about environmental phenomena. As sensor networks come to be wide-spread deployment, security issues become a central concern. So far, the main research focus has been on making sensor networks feasible and useful, and less emphasis has been placed on security. This paper analyzes security challenges in wireless sensor networks and summarizes key issues that need be solved for achieving security in an ad hoc network. It gives an overview of the current state of solutions on such key issues as secure routing, prevention of denial-of-service, and key management service.

TinyCubus: a flexible and adaptive framework sensor networks

Abstract: With the proliferation of sensor networks and sensor network applications, the overall complexity of such systems is continuously increasing. Sensor networks are now heterogeneous in terms of their hardware characteristics and application requirements even within a single network. In addition, the requirements of currently supported applications are expected to change over time. All of this makes developing, deploying and optimizing sensor network applications an extremely difficult task. In this paper, we present the architecture of TinyCubus, a flexible and adaptive cross-layer framework for TinyOS-based sensor networks that aims at providing the necessary infrastructure to cope with the complexity of such systems. TinyCubus consists of a data management framework that selects and adapts both system and data management components, a cross-layer framework that enables optimizations through cross-layer interactions, and a configuration engine that installs components dynamically. Furthermore, we show the feasibility of our architecture by describing and evaluating a code distribution algorithm that uses application knowledge about the sensor topology in order to optimize its behavior.

Field Monitoring Using Sensor-Nodes with a Web Server

Abstract: In order to realize field and environment monitoring over long periods of time, we propose a new method of remote monitoring system that can flexibly and dynamically respond to changes. Field Servers are one of the small monitoring sensor-nodes that are equipped with a Web server to be accessed via the Internet and use wireless LAN to provide a high-speed transmission network differing from traditional sensor-nodes. The monitoring system with Field Servers allows for easy installation, monitoring field information, and remote operation in any field. By mounting the function of a Web server for all modules, we can treat them collectively via the Internet. In order to evaluate the monitoring system, we have managed numerous Field Servers installed in various countries using an agent program. The result of field experiments shows that the system is both safe and effective for remote monitoring applications.

Sensor ontologies: from shallow to deep models

Abstract: This paper presents a practical approach to developing comprehensive sensor ontologies based upon deep knowledge models rather than capturing only superficial sensor attributes. It is proposed that the representation and utilization of deep sensor ontologies would enable a variety of sensor information system applications including sensor parts compatibility determination, dynamic sensor selection and tasking, and reasoning about systems of sensors in which data must be fused and queried from a variety of sensor types within a myriad of environments.

Selection and Navigation of Mobile Sensor Nodes Using a Sensor Network

Abstract: Hybrid sensor networks comprise of mobile and static sensor nodes setup for the purpose of collaboratively performing tasks like sensing a phenomenon or monitoring a region. In this paper, we present a novel approach for navigating a mobile sensor node (MSN) through such a hybrid sensor network. The static sensor nodes in the sensor network guide the MSN to the phenomenon. One or more MSN's are selected based on their proximity to the detected phenomenon. Navigation is accomplished using the concepts of credit based field setup and navigation force from static sensor nodes. Our approach does not require any prior maps of the environment thus, cutting down the cost of the overall system. The simulation results have verified the effectiveness of the proposed approach. In each of the simulation runs, the static sensor nodes were able to successfully guide the MSN towards the phenomenon

Sense: a wireless sensor network simulator

Abstract: A new network simulator, called SENSE, has been developed for simulating wireless sensor networks. The primary design goal is to address such factors as extensibility, reusability, and scalability, and to take into account the needs of different users. The recent progresses in component-based simulation, namely the component-port model and the simulation component classification, provided a sound theoretical foundation for the simulator. Practical issues, such as efficient memory usage, sensor network specific models, were also considered. Consequently, SENSE becomes an ease-of-use and efficient simulator for sensor network research.

SpyGlass: a wireless sensor network visualizer

Abstract: In this paper we present a modular and extensible visualization framework for wireless sensor networks. These networks have typically no means of visualizing their internal state, sensor readings or computational results. Visualization is therefore a key issue to develop and operate these networks. Data emitted by individual sensor nodes is collected by gateway software running on a machine in the sensor network. It is then passed on via TCP/IP to the visualization software on a potentially remote machine. Visualization plug-ins can register to different data types, and visualize the information using a flexible multi-layer mechanism that renders the information on a canvas. Developers can easily adapt existing or develop new custom tailored plug-ins for their specific visualization needs and applications.

Sensor grid: integration of wireless sensor networks and the grid

Abstract: Wireless sensor networks have emerged as an exciting technology for a wide range of important applications that acquire and process information from the physical world. Grid computing has evolved as a standards-based approach for coordinated resource sharing. Sensor grids combine these two promising technologies by extending the grid computing paradigm to the sharing of sensor resources in wireless sensor networks. There are several issues and challenges in the design of sensor grids. In this paper, we propose a sensor grid architecture, called the scalable proxy-based architecture for sensor grid (SPRING), to address these design issues. We also developed a sensor grid testbed to study the design issues of sensor grids and to improve our sensor grid architecture design

Research and analysis on routing protocols for wireless sensor networks

Abstract: Wireless sensor networks (WSNs) are the products which integrate sensor techniques, embedded techniques, distributed. information processing and communication techniques. The appearance of the wireless sensor network is a revolution in information sensing and detection. Recently, both academia and industry have shown great interest in sensor networks. The paper introduces the architecture of the wireless sensor network and WSN features. It then studies recent routing protocols for wireless sensor networks and presents a variety of classifications of them; it also contrasts and compares representative routing protocols. Several future open issues of the wireless sensor networks are put forward.

Development of field programmable modular wireless sensor network nodes for ambient systems

Abstract: The goal of this work is to fabricate robust, miniature, wireless sensor modules. These provide an enabling technology platform to conduct research in creating ambient systems, through implementing wireless sensor network applications. The approach taken is to partition the wireless sensor module into a series of layers with area 25mmx25mm. This modular approach has resulted in the specification of a series of layers, including a field programmable gate array layer for digital signal processing type operations, forming the initial elements of the 25mm sensor node toolkit that can be programmed for use with different sensors depending on application. This paper highlights the development of the sensor, processing, communication and power layers, and the connection approach used to form a robust modular system. Comparisons are made with other wireless sensor nodes and application examples are given.

Environmental Studies with the Sensor Web: Principles and Practice

Abstract: In 1997, the Sensor Web was conceived at the NASA/Jet Propulsion Laboratory (JPL) to take advantage of the increasingly inexpensive, yet sophisticated, mass consumer-market chips for the computer and telecommunication industries and use them to create platforms that share information among themselves and act in concert as a single instrument. This instrument would be embedded into an environment to monitor and even control it. The Sensor Web's purpose is to extract knowledge from the data it collects and use this information to intelligently react and adapt to its surroundings. It links a remote end-user's cognizance with the observed environment. Here, we examine not only current progress in the Sensor Web technology, but also its recent application to problems in hydrology to illustrate the general concepts involved.

A framework for intelligent sensor network with video camera for structural health monitoring of bridges

Abstract: Wireless sensor network (WSN) gives the characteristics of an effective, feasible and fairly reliable monitoring system which shows promise for structural health monitoring (SHM) applications. Monitoring of civil structures generates a large amount of sensor data that is used for structural anomaly detection. Efficiently dealing with this large amount of data in a resource-constrained WSN is a challenge. This paper proposes a, WSN based, novel framework that triggers smart events from sensor data. These events are useful for both intelligent data recording and video camera control. The operation of this framework consists of active & passive sensing modes. In passive mode, selected nodes can intelligently interpret local sensor data to trigger appropriate events. In active mode, most of the sensing nodes perform high frequency sampling and record useful data. Unnecessary data is suppressed which improves the lifespan of the network and simplifies data management.

Algorithms for Wireless Sensor Networks

Abstract: This paper reviews some of the recent advances in the development of algorithms for wireless sensor networks. We focus on sensor deployment and coverage, routing, and sensor fusion.

Current and future trends in sensor networks: a survey

Abstract: Sensor networks consist of a large number of very small nodes that are deployed in some geographical area. The purpose of the network is to sense the environment and report what happens in the area it is deployed in. Sensor networks are used in many applications. In military applications they are used for surveillance and target tracking. In industrial applications, sensor networks are used in monitoring hazardous chemicals. They are also used in monitoring the environment and in early fire warning in forests as well as seismic data collections. Sensor networks face new challenges not known in cellular and ad-hoc wireless networks. In this paper, we report on currents and new trends in sensor networks. We also present some of the challenges and future work in sensor networks.

A robust group-based key management scheme for wireless sensor networks

Abstract: Sensor networks pose security and privacy challenges. To maintain confidentiality of sensor communications, it is challenging to bootstrap secure communications among sensors while making sensor networks highly connected when sensors are randomly deployed. Several existing key management schemes either cannot offer strong resilience against node capture attacks or have overly large memory requirement to achieve a high degree of connectivity, which is measured as the fraction of the size of the largest connected component over the size of the entire sensor network. We propose a group-based key pre-distribution scheme using sensor deployment knowledge. In our scheme, we partition a sensor field into a hexagonal grid. Sensor nodes are divided into groups, each of which is deployed into a cell of the grid. Our scheme consists of a series of slightly different methods, depending on how to distribute secret information among neighboring groups and how much information is to be stored in each node. Experimental results show that our scheme achieves a higher degree of connectivity of the sensor network with a lower memory requirement compared to existing schemes. In addition, our scheme offers a stronger resilience against node capture attacks.

Navigation protocols in sensor networks

Abstract: We develop distributed algorithms for adaptive sensor networks that respond to directing a target through a region of space. We model this problem as an online distributed motion planning problem. Each sensor node senses values in its perception space and has the ability to trigger exceptions events we call “danger” and model as “obstacles”. The danger/obstacle landscape changes over time. We present algorithms for computing distributed maps in perception space and for using these maps to compute adaptive paths for a mobile node that can interact with the sensor network. We give the analysis to the protocol and report on hardware experiments using a physical sensor network consisting of Mote sensors. We also show how to reduce searching space and communication cost using Voronoi diagram.

Towards multi-purpose wireless sensor networks

Abstract: Current wireless sensor network (WSN) architectures are based on the assumption that all sensor nodes are participating in a single global task. In many scenarios, however it will be desirable to use a single sensor network for multiple concurrent applications. In order to enable such multipurpose WSNs efficiently, delimiting each application to its specific set of relevant nodes is one of the key issues that needs to be solved. We present scoping as a general concept for the creation and maintenance of network-wide node subsets and describe a flexible and modular architecture that meets the requirements of multi-purpose WSNs.