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
A radio channel model for D2D communications blocked by single trees in forest environments
(MDPI, 2019) Picallo Guembe, Imanol; Klaina, Hicham; López Iturri, Peio; Aguirre Gallego, Erik; Celaya Echarri, Mikel; Azpilicueta Fernández de las Heras, Leyre; Eguizábal Garrido, Alejandro; Falcone Lanas, Francisco; Alejos, Ana V.; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
In this paper we consider the D2D (Device-to-Device) communication taking place between Wireless Sensor Networks (WSN) elements operating in vegetation environments in order to achieve the radio channel characterization at 2.4 GHz, focusing on the radio links blocked by oak and pine trees modelled from specimens found in a real recreation area located within forest environments. In order to fit and validate a radio channel model for this type of scenarios, both measurements and simulations by means of an in-house developed 3D Ray Launching algorithm have been performed, offering as outcomes the path loss and multipath information of the scenarios under study for forest immersed isolated trees and non-isolated trees. The specific forests, composed of thick in-leaf trees, are called Orgi Forest and Chandebrito, located respectively in Navarre and Galicia, Spain. A geometrical and dielectric model of the trees were created and introduced in the simulation software. We concluded that the scattering produced by the tree can be divided into two zones with different dominant propagation mechanisms: an obstructed line of sight (OLoS) zone far from the tree fitting a log-distance model, and a diffraction zone around the edge of the tree. 2D planes of delay spread value are also presented which similarly reflects the proposed two-zone model.
Open Access
Performance analysis of IEEE 802.15.4 compliant wireless devices for heterogeneous indoor home automation environments
(Hindawi, 2012) Nazábal Urriza, Juan Antonio; López Iturri, Peio; Azpilicueta Fernández de las Heras, Leyre; Falcone Lanas, Francisco; Fernández Valdivielso, Carlos; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua
The influence of topology as well as morphology of complex indoor scenarios in the deployment of wireless sensor networks and wireless systems applied to home and building automation systems is analyzed. The existence of loss mechanisms such as material absorption (walls, furniture, etc.) and strong multipath components as well as the increase in the number of wireless sensors within indoor scenarios increases the relevance in the configuration of the heterogeneous wireless systems. Simulation results by means of empirical-based models are compared with an in-house 3D ray launching code as well as measurement results from wireless sensor networks illustrate the strong influence of the indoor scenario in the overall performance. The use of adequate radioplanning strategies lead to optimal wireless network deployments in terms of capacity, quality of service, and reduced power consumption.
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
Ubiquitous connected train based on train-to-ground and intra-wagon communications capable of providing on trip customized digital services for passengers
(MDPI, 2014) Salaberria, Itziar; Perallos Ruiz, Asier; Azpilicueta Fernández de las Heras, Leyre; Falcone Lanas, Francisco; Carballedo, Roberto; Angulo Martínez, Ignacio; Elejoste Larrucea, Pilar; Bahillo, Alfonso; Astrain Escola, José Javier; Villadangos Alonso, Jesús; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Ingeniería Matemática e Informática; Matematika eta Informatika Ingeniaritza
During the last years, the application of different wireless technologies has been explored in order to enable Internet connectivity from vehicles. In addition, the widespread adoption of smartphones by citizens represents a great opportunity to integrate such nomadic devices inside vehicles in order to provide new and personalized on trip services for passengers. In this paper, a proposal of communication architecture to provide the ubiquitous connectivity needed to enhance the smart train concept is presented and preliminarily tested. It combines an intra-wagon communication system based on nomadic devices connected through a Bluetooth Piconet Network with a highly innovative train-to-ground communication system. In order to validate this communication solution, several tests and simulations have been performed and their results are described in this paper.
Open Access
A hybrid ray launching-diffusion equation approach for propagation prediction in complex indoor environments
(IEEE, 2017) Azpilicueta Fernández de las Heras, Leyre; Falcone Lanas, Francisco; Janaswamy, Ramakrishna; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
A novel and efficient deterministic approach to model radio wave propagation channels in complex indoor environments improving prediction accuracy is proposed. This technique combines a 3-D Ray Launching algorithm based on Geometrical Optics with a Diffusion Equation method based on the equation of transfer. A comparison between the Geometrical Optics only approach and the new method considering the Diffusion Equation has been presented for studying indoor radio wave propagation. The Geometrical Optics-Diffusion Equation method achieves better agreement with measurements, while resulting in high computational efficiency, with approximately 40% savings in simulation time.
Open Access
Implementation and operational analysis of an interactive intensive care unit within a smart health context
(MDPI, 2018) López Iturri, Peio; Aguirre Gallego, Erik; Trigo Vilaseca, Jesús Daniel; Astrain Escola, José Javier; Azpilicueta Fernández de las Heras, Leyre; Serrano Arriezu, Luis Javier; Villadangos Alonso, Jesús; Falcone Lanas, Francisco; Ingeniaritza Elektrikoa eta Elektronikoa; Matematika eta Informatika Ingeniaritza; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica; Ingeniería Matemática e Informática
In the context of hospital management and operation, Intensive Care Units (ICU) are one of the most challenging in terms of time responsiveness and criticality, in which adequate resource management and signal processing play a key role in overall system performance. In this work, a context aware Intensive Care Unit is implemented and analyzed to provide scalable signal acquisition capabilities, as well as to provide tracking and access control. Wireless channel analysis is performed by means of hybrid optimized 3D Ray Launching deterministic simulation to assess potential interference impact as well as to provide required coverage/capacity thresholds for employed transceivers. Wireless system operation within the ICU scenario, considering conventional transceiver operation, is feasible in terms of quality of service for the complete scenario. Extensive measurements of overall interference levels have also been carried out, enabling subsequent adequate coverage/capacity estimations, for a set of Zigbee based nodes. Real system operation has been tested, with ad-hoc designed Zigbee wireless motes, employing lightweight communication protocols to minimize energy and bandwidth usage. An ICU information gathering application and software architecture for Visitor Access Control has been implemented, providing monitoring of the Boxes external doors and the identification of visitors via a RFID system. The results enable a solution to provide ICU access control and tracking capabilities previously not exploited, providing a step forward in the implementation of a Smart Health framework.
Open Access
Analysis of bluetooth-based wireless sensor networks performance in hospital environments
(MDPI, 2016) López Iturri, Peio; Led Ramos, Santiago; Aguirre Gallego, Erik; Azpilicueta Fernández de las Heras, Leyre; Serrano Arriezu, Luis Javier; Falcone Lanas, Francisco; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, a method to analyze the performance of Bluetooth-based Wireless Sensor Networks (WSN) deployed within hospital environments is presented. Due to the complexity that this kind of scenarios exhibit in terms of radio propagation and coexistence with other wireless communication systems and other potential interference sources, the deployment of WSNs becomes a complex task which requires an in-depth radio planning analysis. For that purpose, simulation results obtained with the aid of an in-house developed 3D Ray Launching code are presented. The scenarios under analysis are located at the Hospital of Navarre Complex (HNC), in the city of Pamplona. As hospitals have a wide variety of scenarios, the analysis has been carried out in different zones such as Boxes, where different medical sensors based on Bluetooth communication protocol have been deployed. The simulation results obtained have been validated with measurements within the scenario under analysis, exhibiting Bluetooth-based WSNs performance within hospital environments in terms of coverage/capacity relations. The proposed methodology can aid in obtaining optimal network configuration and hence performance of Bluetooth-based WSNs within medical/health service provision environments.
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
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.