Freshman Engineering Project on Energy Scavenging

This paper describes the design, development and implementation of an energy scavenging project for an introduction to engineering course. The overall objective of the project is to provide students with a hands-on experience on all the components of a renewable energy system. After completing this project students should be able to understand the basic engineering concepts as well as the principles of the design process. Energy scavenging is a form of renewable energy technology at micro or nano scale level. In this project students design and build a small vibrating system that takes the place of the energy source. A piezoelectric material is used to collect the energy produced by the vibrating system. The output of the piezoelectric material is fed to a rectifier circuit whose output charges a battery. Over two hundred freshman engineering students from four different disciplines: civil, computer, electrical, and mechanical have completed this project. Students’ reports, reflection papers, and the results from surveys clearly show that, in addition to be a very appealing project, its objectives are achieved

A MISO UCA Beamforming Dimmable LED System for Indoor Positioning

The use of a multiple input single output (MISO) transmit beamforming system using dimmable light emitting arrays (LEAs) in the form of a uniform circular array (UCA) of transmitters is proposed in this paper. With this technique, visible light communications between a transmitter and a receiver (LED reader) can be achieved with excellent performance and the receiver’s position can be estimated. A hexagonal lattice alignment of LED transmitters is deployed to reduce the coverage holes and the areas of overlapping radiation. As a result, the accuracy of the position estimation is better than when using a typical rectangular grid alignment. The dimming control is done with pulse width modulation (PWM) to obtain an optimal closed loop beamforming and minimum energy consumption with acceptable lighting

Centre for Wireless Communications

Abstract- In this paper, energy efficiency of forward error correction (FEC) coding in ultra wideband (UWB) wireless sensor networks (WSNs) is studied taking into account the characteristics of the physical (PHY) and medium access control (MAC) layers. The underlying goal has been to develop a cross-layer framework that allows the design of energy efficient FEC coding in UWB WSNs. This study is carried out using analytical derivations and simulations. A cross-layer approach, such as the one described here, provides a deeper understanding of the various factors that affect the energy consumption in WSNs, and how FEC coding can improve it. Results clearly show that coding improves the energy efficiency in UWB transceivers. By using the framework introduced here, UWB network designers can analyze the network energy efficiency already in the design phase. I

An Urn Occupancy Approach for Modeling the Energy Consumption of Distributed Beaconing

In past years, ultra wideband technology has attracted great attention from academia and industry for wireless personal area networks and wireless sensor networks. Maintenance of connectivity and exchange of data require an efficient way to manage the devices. Distributed beaconing defined by ECMA-368 is used to manage the network in fully distributed fashion. Distributed beaconing requires that all devices acquire a unique beacon slot, with the beacon period accessed using a slotted Aloha scheme. In this paper, we study the efficiency of distributed beaconing in the presence of k newcomer devices forming a closed system. Efficiency is measured in terms of energy consumption and network set-up delay. ECMA-368 defines two distinct phases: extension and contraction. Both phases are analyzed with particular emphasis on the extension phase by means of an absorbing Markov chain model. The main contributions of this paper are: 1) a systematic approach to model distributed beaconing by formulating two equivalent urn occupancy problems of the extension and contraction phases; 2) the use of exponential generating functions to obtain closed form expressions of the transition probabilities of the absorbing Markov chain; and 3) comparison with computer simulations based on Opnet modeling and with the preexisting literature.JRC.G.6-Security technology assessmen

IMPLEMENTATION ISSUES FOR WIRELESS MEDICAL DEVICES

Recent technological advances in sensors, low-power integrated circuits, and wireless communications have enabled the design of low-cost, miniature, lightweight, and intelligent physiological sensor nodes. Being capable of sensing, processing, and communicating one or more vital signs, these nodes can be seamlessly integrated into wireless personal or body area networks (WPANs or WBANs, respectively) for health monitoring. These networks promise to revolutionize health care by allowing inexpensive, noninvasive, continuous, ambulatory health monitoring with almost real-time updates of medical records via the Internet. Though a number of ongoing research efforts are focusing on various technical, economic, and social issues, many technical hurdles still need to be resolved in order to have flexible, reliable, secure, and power-efficient WBANs suitable for medical applications. This paper discusses implementation issues and describes the authors ’ prototype sensor network for health monitoring that utilizes off-the-shelf 802.15.4 compliant network nodes. The paper presents performance analysis for different health care equipment for 6LoWPAN based wireless network. I