Enhancing wireless performance using reflectors
01 May 2017-pp 1-9
TL;DR: OptRe is proposed which optimally places metallic reflectors — providing a highly reflective surface that can reflect impinging signals almost 100% — in indoor environments to reduce the reflection loss and enhance wireless transmissions.
Abstract: Signal decay is the fundamental problem of wireless communications, especially in an indoor environment where line-of-sight (LOS) paths for signal propagation are often blocked and various indoor objects exacerbate signal fading. There are three reasons for signal decay: long transmission distance, signal penetration, and reflection. In this paper, we propose OptRe which optimally places metallic reflectors — providing a highly reflective surface that can reflect impinging signals almost 100% — in indoor environments to reduce the reflection loss and enhance wireless transmissions. It enhances both WiFi signal and low-power IoT devices without changing their configurations or network protocols. To enable OptRe, we first develop an empirical signal propagation model that can accurately estimate the signal strength and adapt itself to the reflectors' location. Using micro-benchmarks, our empirical signal propagation model is shown to be more accurate than the other existing path loss models. We also optimally place reflectors to maximize the worst-case signal coverage within the target indoor areas. Our extensive experimental evaluation results have shown OptRe to enhance signal strength for different types of wireless signals by almost 2x.
Citations
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TL;DR: In this article , the authors rigorously derive a general reflection model that is applicable to metal re-ectors of any size, any orientation, and any linear polarization.
Abstract: —Wireless communication using fully passive metal reflectors is a promising technique for coverage expansion, signal enhancement, rank improvement and blind-zone compensation, thanks to its appealing features including zero energy con-sumption, ultra low cost, signaling- and maintenance-free, easy deployment and full compatibility with existing and future wireless systems. However, a prevalent understanding for reflection by metal plates is based on Snell’s Law, i.e., signal can only be received when the observation angle equals to the incident angle, which is valid only when the electrical dimension of the metal plate is extremely large. In this paper, we rigorously derive a general reflection model that is applicable to metal reflectors of any size, any orientation, and any linear polarization. The derived model is given compactly in terms of the radar cross section (RCS) of the metal plate, as a function of its physical dimensions and orientation vectors, as well as the wave polarization and the wave deflection vector, i.e., the change of direction from the incident wave direction to the observation direction. Furthermore, experimental results based on actual field measurements are provided to validate the accuracy of our developed model and demonstrate the great potential of communications using metal reflectors.
1 citations
Proceedings Article•
01 Dec 2017TL;DR: This paper has made an attempt to identify these dead zones and proposed a solution to minimize the dead zones in a campus-wide IEEE 802.11g network by measurement of signal strength.
Abstract: The paper is all about dead zone identification in a campus-wide IEEE 802.11g network by measurement of signal strength. IEEE standard 802.11 is a technology for wireless local area networking. In most of the campus-wide networks, there exist some dead zones. Dead zones are the places where there is no network coverage. As a result, the devices or personnel, when enter in these zones will be out of coverage of the network and some of the important and critical information may be lost. In this paper, we have made an attempt to identify these dead zones and proposed a solution to minimize the dead zones. Extensive measurements of signal strength by using Wireless Network analyzer android app have been conducted at various locations in the campus and plotted the dead zones on the Google map of the campus. A solution has been proposed to minimize the dead zones Based on the experimental results and the current location of the access point in the campus.
Cites background from "Enhancing wireless performance usin..."
...They are long transmission distance, signal penetration and reflection [9]....
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Proceedings Article•
TL;DR: RF-Bouncer as mentioned in this paper is a programmable dual-band metasurface that supports concurrent beamforming on two sub-6 ISM bands by configuring the states of the meta-atoms.
Abstract: Offloading the beamforming task from the endpoints to the metasurface installed in the propagation environment has attracted significant attention. Currently, most of the metasurface-based beamforming solutions are designed and optimized for operation on a single ISM band (either 2.4 GHz or 5 GHz). In this paper, we propose RF-Bouncer, a compact, low-cost, simple-structure programmable dual-band metasurface that supports concurrent beamforming on two Sub-6 ISM bands. By configuring the states of the meta-atoms, the metasurface is able to simultaneously steer the incident signals from two bands towards their desired departure angles. We fabricate the metasurface and validate its performance via extensive experiments. Experimental results demonstrate that RF-Bouncer achieves 15.4 dB average signal strength improvement and a 2.49× throughput improvement even with a relatively small 16 × 16 array of meta-atoms.
References
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Proceedings Article•
01 Jan 2005
TL;DR: This book aims to provide a chronology of key events and individuals involved in the development of microelectronics technology over the past 50 years and some of the individuals involved have been identified and named.
Abstract: Alhussein Abouzeid Rensselaer Polytechnic Institute Raviraj Adve University of Toronto Dharma Agrawal University of Cincinnati Walid Ahmed Tyco M/A-COM Sonia Aissa University of Quebec, INRSEMT Huseyin Arslan University of South Florida Nallanathan Arumugam National University of Singapore Saewoong Bahk Seoul National University Claus Bauer Dolby Laboratories Brahim Bensaou Hong Kong University of Science and Technology Rick Blum Lehigh University Michael Buehrer Virginia Tech Antonio Capone Politecnico di Milano Javier Gómez Castellanos National University of Mexico Claude Castelluccia INRIA Henry Chan The Hong Kong Polytechnic University Ajit Chaturvedi Indian Institute of Technology Kanpur Jyh-Cheng Chen National Tsing Hua University Yong Huat Chew Institute for Infocomm Research Tricia Chigan Michigan Tech Dong-Ho Cho Korea Advanced Institute of Science and Tech. Jinho Choi University of New South Wales Carlos Cordeiro Philips Research USA Laurie Cuthbert Queen Mary University of London Arek Dadej University of South Australia Sajal Das University of Texas at Arlington Franco Davoli DIST University of Genoa Xiaodai Dong, University of Alberta Hassan El-sallabi Helsinki University of Technology Ozgur Ercetin Sabanci University Elza Erkip Polytechnic University Romano Fantacci University of Florence Frank Fitzek Aalborg University Mario Freire University of Beira Interior Vincent Gaudet University of Alberta Jairo Gutierrez University of Auckland Michael Hadjitheodosiou University of Maryland Zhu Han University of Maryland College Park Christian Hartmann Technische Universitat Munchen Hossam Hassanein Queen's University Soong Boon Hee Nanyang Technological University Paul Ho Simon Fraser University Antonio Iera University "Mediterranea" of Reggio Calabria Markku Juntti University of Oulu Stefan Kaiser DoCoMo Euro-Labs Nei Kato Tohoku University Dongkyun Kim Kyungpook National University Ryuji Kohno Yokohama National University Bhaskar Krishnamachari University of Southern California Giridhar Krishnamurthy Indian Institute of Technology Madras Lutz Lampe University of British Columbia Bjorn Landfeldt The University of Sydney Peter Langendoerfer IHP Microelectronics Technologies Eddie Law Ryerson University in Toronto
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Book•
01 Jan 1993TL;DR: In this paper, the Lagrangian relaxation and dual ascent tree search were used to solve the graph bisection problem and the graph partition problem, and the traveling salesman problem scheduling problems.
Abstract: Part 1 Introduction: combinatorial problems local and global optima heuristics. Part 2 Simulated annealing: the basic method enhancements and modifications applications conclusions. Part 3 Tabu search: the tabu framework broader aspects of intensification and diversification tabu search applications connections and conclusions. Part 4 Genetic algorithms: basic concepts a simple example extensions and modifications applications conclusions. Part 5 Artificial neural networks: neural networks combinatorial optimization problems the graph bisection problem the graph partition problem the travelling salesman problem scheduling problems deformable templates inequality constraints, the Knapsack problem summary. Part 6 Lagrangian relaxation: overview basic methodology Lagrangian heuristics and problem reduction determination of Lagrange multipliers dual ascent tree search applications conclusions. Part 7 Evaluation of heuristic performance: analytical methods empirical testing statistical inference conclusions.
2,571 citations
"Enhancing wireless performance usin..." refers methods in this paper
...SA is used to search for the optimal solution based on the way that a metal cools down to the optimal state (the annealing process from an initial temperature T to minimal Tmin at a certain cooling rate) [17]....
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01 Jan 1993
TL;DR: The principles of radio propagation in indoor environments are reviewed, the channel is modeled as a linear time-varying filter at each location in the three-dimensional space, and the properties of the filter's impulse response are described.
1,735 citations
"Enhancing wireless performance usin..." refers background in this paper
...Indoor radio propagation has been an active subject of research [6], [7]....
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01 Jul 1993
TL;DR: In this paper, a tutorial survey of radio propagation in indoor environments is presented, where the channel is modeled as a linear time-varying filter at each location in the 3D space, and the properties of the filter's impulse response are described.
Abstract: In this tutorial survey the principles of radio propagation in indoor environments are reviewed. The channel is modeled as a linear time-varying filter at each location in the three-dimensional space, and the properties of the filter's impulse response are described. Theoretical distributions of the sequences of arrival times, amplitudes and phases are presented. Other relevant concepts such as spatial and temporal variations of the channel, large-scale path losses, mean excess delay and RMS delay spread are explored. Propagation characteristics of the indoor and outdoor channels are compared and their major differences are outlined. Previous measurement and modeling efforts are surveyed, and areas for future research are suggested. >
1,696 citations