Showing papers on "Wireless sensor network published in 1997"

Multifunction sensor and network sensor system

Abstract: A multifunction sensor provides a plurality of parameter sensors in one sensor module which can interface with and control operation of one or more processor control systems in an occupied space networked environment such as a commercial building. The multifunction sensor comprises at least an occupancy sensor, an ambient light sensor, and a temperature sensor. A common network communications and control processor is coupled to a common communication transceiver, and are shared in common by the occupancy sensor, the ambient light sensor and the temperature sensor, such that the multifunction sensor can interface with and control operation of one or more processor control systems. A plurality of the multifunction sensors are placed at different locations throughout the building. The multifunction network sensor system further comprises energy management and security controller systems, and a common data communication network which connects to the multifunction sensors and the controller systems to form a local operating network in the building. Each multifunction sensor is assigned a unique location address, and can transmit and receive data, including its own unique address, over the data communication network.

Fixed optic sensor system and distributed sensor network

Abstract: A fixed optic sensor system (200) comprising a sensor system (210), and electronic sub-system (205) and a communications means (215). The system can be used for detecting the presence of various sample (236) properties and in that regard has widespread application by leveraging off various miniaturized sensor configurations including surface plasmon resonance (50), fluorescence (80), light transmission (125) and others (150). In one embodiment, the communications means (215) is a wireless transmitter/receiver. In another embodiment, a hand held instrument (358) can be used on-site and communicates with the sensor (350) to receive sample (352) related data and transmit it to a remote processing system (370) for further analysis. In yet another embodiment, a hand held instrument (403) has a plurality of cardiac marker binding ligands (400) deposited on the sensor/sample interface providing a medical diagnosis and point-of-care device (403).

Design and retrofit of sensor networks in process plants

Abstract: A novel procedure to find cost-optimal sensor networks is proposed. Cost is minimized subject to qualifying constraints that are related to certain requirements of data reconciliation. One basic qualifying constraint is a desired level of precision of reconciled values for a selected set of variables. Since precision requirements lead to multiple solutions, other qualifying constraints are proposed. These constraints are availability, resilience, and error detectability. Definitions for these terms are given and their impact on the results is presented.

On the cost structure of future wideband wireless access

Abstract: Wireless data services have attracted increasing attention in the last few years. Boosted by the massive use of popular Internet-based services such as email, WWW, etc., wireless wideband networks capable of supporting mobile multimedia services are being planned. An important requirement has been postulated for these wideband services-they cannot be substantially more expensive than the voice services offered today. Connection revenues cannot be expected to be proportional to the bandwidth provided. We use some simple cost models to analyze the cost structure of some proposed wireless infrastructure architectures supporting multimedia services. Both infrastructural costs and spectrum costs are included in the analysis. Results show that universal wideband coverage has an end-user connection cost that is almost directly proportional to the bandwidth provided. This is in contrast with wireline optical networks were the bandwidth cost is virtually "flat". We show further that for some hierarchical architectures, with wideband "hot-spot" service supplemented by wide-area, low data rate, coverage there exist some scenarios where a more favorable cost structure more suited for wideband multimedia applications can be achieved. The implication of the results is to use multimedia terminals and services tolerant to variable data rates and communication quality not only as proposed in a transient introduction phase, but also in the long-term perspective.

Low power wireless communication and signal processing circuits for distributed microsensors

Abstract: Low power wireless sensor networks provide a new monitoring and control capability for civil and military applications in transportation, manufacturing, biomedical technology, environmental management, and safety and security systems. Low power integrated CMOS systems are being developed for microsensors, signal processors, microcontrollers, communication transceivers and network access control. This paper covers recent advances in CMOS-based microsensor systems, low power signal processing and RF communication circuits. Communication circuits include the demonstration of a 20 /spl mu/A supply current, 860 MHz, low phase noise CMOS local oscillator.

Active diagnosis by self-organization: an approach by the immune network metaphor

Abstract: We propose a concept of active diagnosis that differs from the conventional passive (i.e. event-driven) diagnosis in temporal (diagnosis is carried out by always monitoring normal condition as opposed to identifying faulty only when abnormal condition is detected) sense as well as spatial (diagnosis is carried out by agents distributed in the sensor network) sense. As one way of realizing active diagnosis, we present immunity-based agents approach based on the self creating, monitoring, and maintaining feature of immune systems. We apply the approach to process diagnosis where the agents are defined on the sensor network. Each agent corresponding to sensor or process constraint evaluates a kind of reliability by communicating other agents. System level recognition of sensor/process fault can be attained by continuously and mutually monitoring and maintaining consistency among sensor values and process constraints.

Fault detection and isolation and sensor network design

Abstract: The model-based approach to fault detection and isolation in automated process has received considerable attention during the past two decades. One of the approaches to facilitate fault isolation is to design a structured residual set. The term structured here means that each residual is designed to be sensitive to a certain group of faults and insensitive to others. However, despite this issue has been recognised for a long time, the problem of designing such residuals is not completely solved. In the context of linear static systems, this paper proposes a new method for sensor network design respecting some sensor failure detectability and isolability requirements.

Multiple access to SAW sensors using matched filter properties

Abstract: In this paper we present a method of solving the problem of access to more than one passive surface acoustic wave (SAW) sensor in the range of a single interrogation system. The sensor informations of the SAW sensors are evaluated almost simultaneously by use of the correlation property of BPSK-coded sensors. We show the principal concept, mathematical simulations, numerical estimations and finally an overview of the design of such a SAW sensor system.

Sensor-to-sensor target association in a network of passive sensors

Abstract: This paper address the problem of sensor-to sensor target association in a distributed passive sensor network. If two or more targets are coplanar with two sensors, ghosts occur among the intersections of line-of-sights. To cancel these ghosts, the authors propose a new association method in which they track angles and angular rates of targets being viewed by each sensor and use not only angle but also angular rate information in the association process. The performance of the proposed method is investigated through Monte Carlo simulation.

Fixed light sensor and distributed sensor network

Abstract: PROBLEM TO BE SOLVED: To provide a (bio)chemical detecting system miniaturized and integrated so as to be furnished to a further analysis by making the number of persons of the job site gather sample data at a job site, processing, analyzing and storing this data, and transferring it to a local or centralized server SOLUTION: A fixed light sensor system 200 has a sensor sub-system 205, an electronic sub-system 205 and a communication sub-system 215 This system can be used to detect the existence of various samples 236, and in that point, it has the widely prevailed application by thoroughly introducing various downsized sensor constitutions containing surface plasmon resonance, fluorescence, light transmission and its other constitutive element

Error correction strategies for wireless ATM

Abstract: Forward error correction coding (FEC) is a widely used method to improve transmission quality in modern communication systems. This paperpresents some aspects on the application of advanced error correction con cepts to recent wireless ATM developments. The target bit error rate and the mapping of the wireless connection quality to the ATM service classes are discussed. Some considerations on the issue of code selection with respect to block size, scalability, complexity and performance are presented. We propose methodsfor comparing the performance of codes at the example of various convolutional codes and Reed-Solomon codes. The impact of the radio environment on the FEC codes is addressed and the code performance is evaluated by simulations using a Gilbert Elliott channel model.

Distributed micromachined sensor networks

Abstract: Researchers at the Honeywell Technology Center are currently developing a new type of high-performance optical sensor which is a `hybrid' micromachined silicon/fiber optic sensor that utilizes the best attributes of each technology. Fiber optics provides a nearly noise free method to read out the sensor without electrical power required at the measurement point. The micromachined silicon STORM (Sensor Transduction by Optically Resonant Microbeams) devices provide a method to design many different types of sensors such as temperature, pressure, acceleration, or magnetic field, and report the sensor data using FM encoding methods. Testing results have demonstrated relaxed alignment tolerance in packaging these devices with excellent SNR. Networks of 16 or more sensors are currently being developed.

Mobile Computing

Abstract: Mobile Computing is designed to serve as a textbook for students in the disciplines of computer science and engineering, electronics and communication engineering, and information technology. It describes the basic concepts of mobile computing and provides technical information about the various aspects of the subject as also the latest technologies that are currently in use. The first few chapters present a balanced view of mobile computing as well as mobile communication, including the 2G and 3G communication systems, mobile IP, and mobile TCP. The subsequent chapters provide a systematic explanation of mobile computing as a discipline in itself. The book provides an in-depth coverage of databases in mobile systems, methods of data caching, dissemination and synchronization, Bluetooth, IrDA and ZigBee protocols, data security, mobile ad hoc and wireless sensor networks, and programming languages and operating systems for mobile computing devices. Written in an easy-to-understand and student-friendly manner, the book includes several illustrative examples and sample codes. A comprehensive set of exercises is included at the end of each chapter

Smart sensor networks for robotic sensor skins

Abstract: Data acquisition and data fusion of large numbers of sensors present unique challenges for control systems designers and applications engineers alike In recent years the sensors industry has been moving towards the use of smart sensors, fieldbus networks, and localized smart processes Merritt Systems Inc of Rockledge, Florida, has been in the forefront of these developments since 1987 when it started pursuing the development of large sensor networks for robotic obstacle avoidance As a result of this work a number of unique smart sensors and network technologies have been developed which have a wide range of applications beyond robotics These include: one of industry’s first smart sensors, smart sensor networks, PC‐based data acquisition and control systems, and novel robotic modelling and motion planning algorithms Whenever large networks of sensors with mixed sensing media are used, this technology has far‐reaching applications to industry and the research community

Network management of wireless tactical networks

Abstract: This paper presents a network layer protocol developed for tactical multimedia networks in the forward area. The proposed network is an autonomous fully distributed wireless ATM network. The structure of the proposed network is hierarchical and allows for rapid deployment and dynamic reconfiguration of wireless stations. Nodes are organized into clusters. The cluster heads are analogous to the base stations in a conventional ATM and they act as the local coordinators to support services that include conventional data applications as well as multimedia (video, voice and data) applications with QoS (quality-of-service) guarantees. The proposed protocols are also intended to provide seamless internetworking with other wired ATM local and wide area networks. The algorithms are distributed for simple implementation and ease of mobility management. A wireless VP/VC concept is described to provide ATM cell routing and connections in the network. Routing and the provision for efficient utilization of the available bandwidth are major problems for supporting multimedia traffic in a wireless network. Call management, network management, and signaling are designed for simplicity. Restoration schemes are also proposed to resolve the connectivity problems associated with link or node failures.

PCS registration and call delivery in broadband wireless networks

Abstract: There is a growing interest in the research community in mechanisms that transport asynchronous transfer mode (ATM) cells over a wireless link (wireless-ATM), and in wireless access to ATM backbone networks (broadband wireless networking). This paper presents an architecture for broadband wireless networking that supports PCS (personal communication services) using an ATM backbone. We develop analytical and simulation models to measure the delay of PCS registration and call delivery. The performance models are illustrated with numerical examples that reveal the high sensitivity to the processing speed of network entities. Their agreement provides a first cut engineering approximation that can easily be applied to other networks and systems.

Development of a fiber optic sensor network for naval applications

Abstract: This paper describes the development of a complete fiber optic sensor network demonstrator, installed on a naval warfare simulator system. It incorporates a 64 on/off multiplexed optical sensor network together with single point analog optical sensors. A complete description of the system is given showing the different sensors that have been developed and their specific applications. We also discuss the experimental results and the potential advantages of this technology for naval systems.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A review of proposed MAC protocols for high-speed wireless networks

Abstract: Following an introduction and brief overview of media access control protocols, this paper presents a review of the current literature on MAC protocols and bandwidth allocation strategies for high speed wireless systems. The four protocols reviewed in this paper range from simple Aloha-type algorithms to relatively complex polling schemes. An attempt is also made to compare the protocols based on their technical merits.

Spatial- and Wavelength-Division-Multiplexed in-Fibre Bragg Grating Sensor Network for Smart Structures

Abstract: Embedded in-fibre Bragg grating (FBG) sensors appear to be ideally suited for structural health and usage monitoring of modern composite materials for aerospace and civil engineering-based applications as they have the following distinguishing advantages compared with conventional electrical sensors: (1) immunity to electromagnetic interference; (2) integration into composite materials without degration or significantly compromising the strength of the host material; (3) capacity of multiplexing many sensors in a single fibre lead allowing quasi-distributing measurement; (4) capacity of mass-production with good repeatability, making them potentially competitive with conventional electrical strain sensors.1 For these applications, it is necessary that the FBG sensors, embedded in or attached to the structure to be monitored, can be multiplexed efficiently to form a quasi-distributed network. So far, several multiplexing schemes for FBG’s, such as wavelength-division multiplexing (WDM), time-division multiplexing (TDM), and spatial-division multiplexing (SDM),2–5 have been investigated. The series multiplexing topologies, such as WDM and TDM, which are based on a single fibre link arrangement, are very efficient in power usage. The parallel topologies, such as SDM, allow each FBG sensor in the network to be operated independently, interchangeable and replaceable in the event of damage. For practical applications, it is necessary to combine both series and parallel topologies in order to create a real 2-D quasi-distributed FBG sensor network.

Random array processing for micromachined sensor network

Abstract: This paper considers 'blind beamforming' operations on a wireless network of randomly distributed MEM sensors. Maximum power collection criterion is proposed and results in array weights obtained from the eigenvector corresponding to largest eigenvalue of a matrix eigenvalue problem. Theoretical justification of this approach to an extension of Szego's asymptotic distribution of eigenvalues is provided. Numerical results on propagation time delay estimation and loss of coherency due to propagation disturbances are presented.