Editorial
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| Title | Editorial |
| Authors | |
| Abstract | Wireless communications are currently omnipresent and their complete pervasiness is often described as the nexttelecommunications frontier. As such, confined environments have received much attention as such particularenvironments present significant opportunities and markets niche for the wireless industry. The mining industry, with itsworldwide presence and considerable impact, is such a market. Wireless technology can be an important lever toimprove the competing advantage of the mining industry in developed countries and to increase operational safety inemerging economies. In fact, telecommunication is the principal asset for automation in the mining industry, allowingthe establishment of a global operating program with localization and remote control of mobile equipments. Thespecific characteristics of the underground environment, and other types of confined surroundings, present importantdesign challenges and are at the origin of novel research orientations. This conference targeted university researchersand industry specialists having realized or interested by original research and innovative applications, or by the analysisof in-situ experiments, related to telecommunications in a confined area (basement, vehicle) or an undergroundenvironment (for example urban basement, tunnel, underground city, mine, shelter).This special issue presents nine selected papers from the International Conferences on Wireless Communications inUnderground and Confined Areas, held in Val-d’Or, Canada, 25-27 August 2008. The guest editors selected the bestpapers from the communications track of the Conference. The authors of these selected papers produced extendedversions of their conference papers, which were further developed through two rounds of reviews.Wireless communication system performance in confined areas is significantly influenced by its peculiar channelpropagation characteristics. The ability to identify propagation phenomena by proposed propagation models orexperiments enables the adaptation of communications system design for these areas. Furthermore, the accuracy ofthese models impacts propagation ranges, threshold reception, adaptation of dynamic links and the performance ofmultiple antennas with spatial multiplexing techniques in such environments.As presented in paper 1, “Radio Wave Propagation in Arched Cross Section Tunnels – Simulations andMeasurements”, by E. Masson et al., wireless communication systems have been developed for train infrastructurecommunication needs related to railway or mass transit applications. These systems are able to operate in tunnelenvironments. In this context, specific radio planning tools have to be developed to optimize system deployment.Realistic tunnels geometries are generally of rectangular cross section or arch-shaped. Furthermore, they are mostlycurved. In this paper, the authors propose an approach to model radio wave propagation in 2.4 GHz and 5.8 GHzfrequency bands in straight arch-shaped tunnels using tessellation in multi-facets. While paper 1 gives a model based ona Ray Tracing tool using the image method, paper 2, “Modified 2D Finite-Difference Time-Domain Based Tunnel PathLoss Prediction for Wireless Sensor Network Applications”, by Yan Wu et al., presents a Propagation Path Loss (PL)Model, which describes the power loss versus distance between the transmitter and the receiver for the tunnelenvironment. In this paper, experimental results obtained from conducting close-to-wall measurements at 868MHz and2.45GHz in curved arched-shaped tunnels are presented along with predictions made using a newly proposed modified2D Finite-Difference Time-Domain (FDTD) method.Paper 3, “Modeling and Understanding MIMO propagation in Tunnels”, by Jose-Maria Molina-Garcia-Pardo et al.presents an application of modal theory for interpreting experimental results of the electromagnetic field variation alonga tunnel. The transmitting frequency is assumed to be high enough so that the tunnel behaves as an oversizedwaveguide. Then, for a Multiple-Input Multiple-Output channel, theoretical results of the channel capacity are given.Paper 4, “On the importance of the MIMO channel correlation in underground railway tunnels”, by Y. Cocheril et al.,deals also with MIMO channel modeling according to the correlation level in underground railway tunnels for variousantenna configurations for the transmitting and receiving arrays. MIMO channel matrices have been computed with a3D ray-tracing based software at 2.4 GHz and 5.8 GHz in two different tunnel environments.Paper 5, “Time-Reversal UWB Wireless Communication-Based Train Control in Tunnel”, by Hassane Saghir et al.,reports an evaluation of UWB radio technology and Time-Reversal (TR) technique in tunnel environments for train-towaysidecommunication. UWB technology has the potential to offer simultaneous ground-to train communication, trainlocation and obstacle detection in front of the trains. This paper deals with deterministic channel modeling and itscharacterization in tunnel environment.Another research area for wireless underground communication is Through-The-Earth (TTE) communication aspresented in paper 6, “Improving Medium Access In Through-The-Earth VLF-LF Communications”, by VanessaBataller et al.Most research advances in these areas are related to a final application. As presented in paper 7, “Radio proximitydetection in a WSN to localize mobile entities within a confined area”, by Chakib Baouche et al., a solution to localizemobile entities within a confined area consists in deploying a Wireless Sensor Network (WSN), made of energy-autonomous devices. The authors propose that the position of a mobile be given relatively to a set of tag nodes deployed in the zone of activity and signaling their position. In a symmetrical way, each mobile node is announced periodically thus allowing for mutual detection of radio proximity (tag-mobile or mobile-mobile). During contact, the nodes are able to share and store the information required by the localization application. This information is then largely scattered by using the mobility of modes to carry data up to the application collection points. This leads to the issue of the choice of the medium access method and its performance for proximity detection in a cell covered by a tag node.While paper 7 focuses on network properties to locate a mobile, paper 8, "Neural Networks for Fingerprinting-Based Indoor Localization using Ultr-Wideband", by Anthony Taok et al., discusses the use of neural networks in an underground radio-localization system using UWB as the physical wireless propagation medium and combined with fingerprinting-geolocation and neural network techniques.The last paper, "A Novel Interference Safety Margin For cognitive Radio manet Using Smart Antennas", by Mathieu Boutin et al., proposes a new interference estimation technique for the deployment of a smart-antenna-equipped MANET (Mobile Ad hoc NETwork), acting as a secondary network, sharing the same scarce frequency band as many legacy fixed antennas (primary network) in the same area. The proposed technique offers great potential, for the deployment of a cognitive MANET, since advances in milimeter radio waves technologies will soon make smart antennas easily portable in size.In closing, we would like to thank reviewers and authors, who, indifferent ways, have contributed to this Special Issue. We would like to acknowledge all the other authors who have submitted their contributions for this issue. We also acknowledge the exceptional effort by the Editorial Board of the Journal of Communications throughout this process. |
| Publisher | ACADEMY PUBLISHER |
| Date | 2009-05-01 |
| Source | Journal of Communications Vol 4, No 4 (2009): Special Issue: Wireless Communications in Underground and Confined Areas |
| Rights | Copyright © ACADEMY PUBLISHER - All Rights Reserved.To request permission, please check out URL: http://www.academypublisher.com/copyrightpermission.html. |