Open Access
Analysis of wireless sensor network topology and estimation of optimal network deployment by deterministic radio channel characterization
(MDPI, 2015) Aguirre Gallego, Erik; López Iturri, Peio; Azpilicueta Fernández de las Heras, Leyre; Astrain Escola, José Javier; Villadangos Alonso, Jesús; Falcone Lanas, Francisco; Ingeniería Eléctrica y Electrónica; Ingeniería Matemática e Informática; Ingeniaritza Elektrikoa eta Elektronikoa; Matematika eta Informatika Ingeniaritza
One of the main challenges in the implementation and design of context-aware scenarios is the adequate deployment strategy for Wireless Sensor Networks (WSNs), mainly due to the strong dependence of the radiofrequency physical layer with the surrounding media, which can lead to non-optimal network designs. In this work, radioplanning analysis for WSN deployment is proposed by employing a deterministic 3D ray launching technique in order to provide insight into complex wireless channel behavior in context-aware indoor scenarios. The proposed radioplanning procedure is validated with a testbed implemented with a Mobile Ad Hoc Network WSN following a chain configuration, enabling the analysis and assessment of a rich variety of parameters, such as received signal level, signal quality and estimation of power consumption. The adoption of deterministic radio channel techniques allows the design and further deployment of WSNs in heterogeneous wireless scenarios with optimized behavior in terms of coverage, capacity, quality of service and energy consumption.
Open Access
Integration of autonomous wireless sensor networks in academic school gardens
(MDPI, 2018) López Iturri, Peio; Celaya Echarri, Mikel; Azpilicueta Fernández de las Heras, Leyre; Aguirre Gallego, Erik; Astrain Escola, José Javier; Villadangos Alonso, Jesús; Falcone Lanas, Francisco; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In this work, the combination of capabilities provided by Wireless Sensor Networks (WSN) with parameter observation in a school garden is employed in order to provide an environment for school garden integration as a complementary educational activity in primary schools. Wireless transceivers with energy harvesting capabilities are employed in order to provide autonomous system operation, combined with an ad-hoc implemented application called MySchoolGardenApp, based on a modular software architecture. The system enables direct parameter observation, data analysis and processing capabilities, which can be employed by students in a cloud based platform. Providing remote data access allows the adaptation of content to specific classroom/homework needs. The proposed monitoring WSN has been deployed in an orchard located in the schoolyard of a primary school, which has been built with EnOcean's energy harvesting modules, providing an optimized node device as well network layout. For the assessment of the wireless link quality and the deployment of the modules, especially the central module which needs to receive directly the signals of all the sensor modules, simulation results obtained by an in-house developed 3D Ray Launching deterministic method have been used, providing coverage/capacity estimations applicable to the specific school environment case. Preliminary trials with MySchoolGardenApp have been performed, showing the feasibility of the proposed platform as an educational resource in schools, with application in specific natural science course content, development of technological skills and the extension of monitoring capabilities to new context-aware applications.
Open Access
Estimation of radiofrequency power leakage from microwave ovens for dosimetric assessment at nonionizing radiation exposure levels
(Hindawi, 2015) López Iturri, Peio; Miguel Bilbao, Silvia de; Aguirre Gallego, Erik; Azpilicueta Fernández de las Heras, Leyre; Falcone Lanas, Francisco; Ramos González, Victoria; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
The electromagnetic field leakage levels of nonionizing radiation from a microwave oven have been estimated within a complex indoor scenario. By employing a hybrid simulation technique, based on coupling full wave simulation with an in-house developed deterministic 3D ray launching code, estimations of the observed electric field values can be obtained for the complete indoor scenario. The microwave oven can be modeled as a time- and frequency-dependent radiating source, in which leakage, basically from the microwave oven door, is propagated along the complete indoor scenario interacting with all of the elements present in it. Thismethod can be of aid in order to assess the impact of such devices on expected exposure levels, allowing adequate minimization strategies such as optimal location to be applied.
Open Access
Characterization of wireless channel impact on wireless sensor network performance in public transportation buses
(IEEE, 2015) Azpilicueta Fernández de las Heras, Leyre; López Iturri, Peio; Aguirre Gallego, Erik; Astrain Escola, José Javier; Villadangos Alonso, Jesús; Zubiri Segura, Cristóbal; Falcone Lanas, Francisco; Ingeniería Eléctrica y Electrónica; Ingeniería Matemática e Informática; Ingeniaritza Elektrikoa eta Elektronikoa; Matematika eta Informatika Ingeniaritza
Wireless communications systems are growing rapidly during the last two decades and they are gaining a significant role for multiple communication tasks within public transportation buses. In this work, the impact of topology and morphology of different types of urban buses is analyzed with the aid of an in-house developed 3D Ray Launching code and compared with on-board measurements of a deployed Wireless Sensor Network. The presence of human beings has been taken into account, showing a significant influence in the signal attenuation in the case of considering persons. In addition, the statistical analysis of simulation results considering both large and small-scale fading has been performed, providing good agreement with statistics for typical indoor environments. In addition, a Wireless Sensor Network has been programmed and deployed within the buses in order to analyze topological impact with overall system performance, with the aim of minimizing the energy consumption as well as non-desired interference levels. The use of deterministic techniques destined to consider the inherent complexity of the buses can aid in wireless system planning in order to minimize power consumption and increase overall system capacity.
Open Access
Analysis of radio wave propagation for ISM 2.4 GHz wireless sensor networks in inhomogeneous vegetation environments
(MDPI, 2014) Azpilicueta Fernández de las Heras, Leyre; López Iturri, Peio; Aguirre Gallego, Erik; Mateo Zozaya, Ignacio; Astrain Escola, José Javier; Villadangos Alonso, Jesús; Falcone Lanas, Francisco; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Ingeniería Matemática e Informática; Matematika eta Informatika Ingeniaritza
The use of wireless networks has experienced exponential growth due to the improvements in terms of battery life and low consumption of the devices. However, it is compulsory to conduct previous radio propagation analysis when deploying a wireless sensor network. These studies are necessary to perform an estimation of the range coverage, in order to optimize the distance between devices in an actual network deployment. In this work, the radio channel characterization for ISM 2.4 GHz Wireless Sensor Networks (WSNs) in an inhomogeneous vegetation environment has been analyzed. This analysis allows designing environment monitoring tools based on ZigBee and WiFi where WSN and smartphones cooperate, providing rich and customized monitoring information to users in a friendly manner. The impact of topology as well as morphology of the environment is assessed by means of an in-house developed 3D Ray Launching code, to emulate the realistic operation in the framework of the scenario. Experimental results gathered from a measurement campaign conducted by deploying a ZigBee Wireless Sensor Network, are analyzed and compared with simulations in this paper. The scenario where this network is intended to operate is a combination of buildings and diverse vegetation species. To gain insight in the effects of radio propagation, a simplified vegetation model has been developed, considering the material parameters and simplified geometry embedded in the simulation scenario. An initial location-based application has been implemented in a real scenario, to test the functionality within a context aware scenario. The use of deterministic tools can aid to know the impact of the topological influence in the deployment of the optimal Wireless Sensor Network in terms of capacity, coverage and energy consumption, making the use of these systems attractive for multiple applications in inhomogeneous vegetation environments.
Open Access
Optimized wireless channel characterization in large complex environments by hybrid ray launching-collaborative filtering approach
(IEEE, 2017) Casino, Fran; Azpilicueta Fernández de las Heras, Leyre; López Iturri, Peio; Aguirre Gallego, Erik; Falcone Lanas, Francisco; Solanas, Agustí; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Simulation techniques based on deterministic methods such as Ray Tracing and Ray Launching, are widely used to perform radioplanning tasks. However, the quality of the simulations depends on the number of rays and the angular resolution. The computational cost of these simulations in High Definition prevents their use in complex environments and their Low Definition counterparts are used instead. In this article we propose a technique based on collaborative filtering to lessen the poor quality problems of Low Definition simulations. We show that our approach obtains results very similar to those of High Definition in much less time. Also, we compare our approach with other well-known techniques and we show that it performs better in terms of accuracy and precision. The use of combined deterministic/collaborative filtering techniques allows the estimation of radioplanning tasks in large, complex scenarios with a potentially large amount of transceivers.
Open Access
Aplicación de sistemas RFID y su implementación en el sector logístico
(2010) Aguirre Gallego, Erik; Falcone Lanas, Francisco; Escuela Técnica Superior de Ingenieros Industriales y de Telecomunicación; Telekomunikazio eta Industria Ingeniarien Goi Mailako Eskola Teknikoa; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Este proyecto se centra en la tecnología RFID aplicada al ámbito logístico y pretende ofrecer tanto nociones básicas de la tecnología y sus aplicaciones en este ámbito, como un completo estudio radioeléctrico tanto teórico como practico de diferentes entornos. Para transmitir los conceptos básicos, se presenta la utilidad de este sistema en logística apoyada en casos de estudio previos y todos los conceptos teóricos necesarios, empezando por la base radioeléctrica, todos los fundamentos de la tecnología RFID y por último describiendo los modelos empíricos usados. Por último se presenta el estudio radioeléctrico, comparando resultados teóricos obtenidos empíricamente y con modelo de trazado de rayos con medidas experimentales en diversos entornos, uno de ellos logístico. Además se evalúa la posibilidad de implantación de un sistema RFID real en este último entorno. De todo este proceso se obtienen muchas conclusiones interesantes.
Open Access
Radio characterization for ISM 2.4 GHz wireless sensor networks for judo monitoring applications
(MDPI, 2014) López Iturri, Peio; Aguirre Gallego, Erik; Azpilicueta Fernández de las Heras, Leyre; Astrain Escola, José Javier; Villadangos Alonso, Jesús; Falcone Lanas, Francisco; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Ingeniería Matemática e Informática; Matematika eta Informatika Ingeniaritza
In this work, the characterization of the radio channel for ISM 2.4GHz Wireless Sensor Networks (WSNs) for judo applications is presented. The environments where judo activity is held are usually complex indoor scenarios in terms of radiopropagation due to their morphology, the presence of humans and the electromagnetic interference generated by personal portable devices, wireless microphones and other wireless systems used by the media. For the assessment of the impact that the topology and the morphology of these environments have on electromagnetic propagation, an in-house developed 3D ray-launching software has been used in this study. Time domain results as well as estimations of received power level have been obtained for the complete volume of a training venue of a local judo club’s facilities with a contest area with the dimensions specified by the International Judo Federation (IJF) for international competitions. The obtained simulation results have been compared with measurements, which have been carried out deploying ZigBee-compliant XBee Pro modules at presented scenario, using approved Judogis (jacket, trousers and belt). The analysis is completed with the inclusion of an in-house human body computational model. Such analysis has allowed the design and development of an in house application devoted to monitor the practice of judo, in order to aid referee activities, training routines and to enhance spectator experience.
Open Access
Analysis of radio wave propagation for ISM 2.4GHz wireless sensor networks in inhomogeneous vegetation environments
(2014) Azpilicueta Fernández de las Heras, Leyre; López Iturri, Peio; Aguirre Gallego, Erik; Astrain Escola, José Javier; Villadangos Alonso, Jesús; Falcone Lanas, Francisco; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Ingeniería Matemática e Informática; Matematika eta Informatika Ingeniaritza
The use of wireless networks has been extended in an exponential growing due to the improvement in terms of battery life and low consumption of the devices. However, it is highly important to conduct previous radio propagation analysis when deploying a wireless sensor network. These studies are necessary to perform an estimation of the range coverage, in order to optimize the distance between devices in an actual network deployment. In this work, the radio channel characterization for ISM 2.4GHz Wireless Sensor Networks (WSN) in an inhomogeneous vegetation environment has been analyzed. The impact of topology as well as morphology of the environment is assessed by means of an in-house developed 3D Ray Launching code, to emulate the realistic operation in the framework of the scenario. Experimental results gathered from a measurements campaign conducted by deploying a ZigBee Wireless Sensor Network, are analyzed and compared with simulations in this paper. The scenario where this network is intended to operate is a combination of buildings and diverse vegetation species. To gain insight in the effects of radio propagation, a simplified vegetation model has been developed, considering the material parameters and simplified geometry embedded in the simulation scenario. The use of deterministic tools can aid to know the impact of the topological influence in the deployment of the optimal Wireless Sensor Network in terms of capacity, coverage and energy consumption, making the use of these systems attractive for multiple applications in inhomogeneous vegetation environments.
Open Access
Zigbee radio channel analysis in a complex vehicular environment [wireless corner]
(IEEE, 2014) Rajo-Iglesias, Eva; López Iturri, Peio; Aguirre Gallego, Erik; Azpilicueta Fernández de las Heras, Leyre; Garate Fernández, Uxue; Falcone Lanas, Francisco; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, the influence of topology and morphology of a particularly complex scenario for the deployment of ZigBee wireless sensor networks is analyzed. This complex scenario is a car. The existence of loss mechanisms such as material absorption (seats, dashboard, etc.) and strong multipath components due to the great number of obstacles and the metallic environment (bodywork), as well as the growing demand for wireless systems within a vehicle emphasizes the importance of the configuration of the heterogeneous intra-car wireless systems. Measurement results as well as simulation results by means of an in-house 3D ray launching algorithm illustrate the strong influence of this complex scenario in the overall performance of the intra-car wireless sensor network. Results also show that ZigBee is a viable technology for successfully deploying intra-car wireless sensor networks.