Open Access
Spatial characterization of personal RF-EMF exposure in public transportation buses
(IEEE, 2019) Celaya Echarri, Mikel; Azpilicueta Fernández de las Heras, Leyre; López Iturri, Peio; Aguirre Gallego, Erik; Miguel Bilbao, Silvia de; Ramos, Victoria; Falcone Lanas, Francisco; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
New services and applications within vehicular environments employ multiple wireless communication systems, within a Heterogeneous Network framework. In this context, evaluation of electromagnetic field impact is compulsory, in order to warrant compliance with current exposure limits. In this work, E-field strength distribution within urban transportation buses is studied, in which different types of buses as well as network configurations are considered. E-field estimations are obtained within the complete interior volume of the urban buses, considering all of the characteristics in terms of bus structure and materials employed, by means of an in-house developed deterministic 3D Ray-Launching (3D-RL) code. In this way, relevant phenomena in terms of electromagnetic propagation and interaction are considered, such as multipath propagation and shadowing, which determine exposure levels as a function of transceiver location within the bus scenarios. The behavior in terms of E-field distribution of wireless Public Land Mobile communication systems within transportation buses have been analyzed by means of measurement campaigns employing personal exposimeter devices. In addition, E-field volumetric distributions by means of 3D-RL simulations have been obtained as a function of user distribution within the buses, with the aim of analyzing the impact of user presence within complex intra-vehicular indoor scenarios such as urban transportation buses. A comparison with current exposure limits given by currently adopted standards is obtained, showing that E-field levels were below the aforementioned limits. The use of deterministic simulation techniques based on 3D-RL enables E-field exposure analysis in complex indoor scenarios, offering an optimized balance between accuracy and computational cost. These results and the proposed simulation methodology, can aid in an adequate assessment of human exposure to non-ionizing radiofrequency fields in public transportation buses, considering the impact of the morphology and the topology of vehicles, for current as well as for future wireless technologies and exposure limits.
Open Access
Deterministic wireless channel characterization towards the integration of communication capabilities to enable context aware industrial internet of thing environments
(Springer, 2022) Picallo Guembe, Imanol; López Iturri, Peio; Celaya Echarri, Mikel; Azpilicueta Fernández de las Heras, Leyre; Falcone Lanas, Francisco; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
In order to provide interactive capabilities within the context of Internet of Thing (IoT) applications, wireless communication systems play a key role, owing to in-herent mobility, ubiquity and ease of deployment. However, to comply with Quality of Service (QoS) and Quality of Experience (QoE) metrics, coverage/capacity analysis must be performed, to account for the impact of signal blockage as well as multiple interference sources. This analysis is especially complex in the case of indoor scenarios, such as those derived from Industrial Internet of Things (IIoT). In this work, a fully volumetric approach based on hybrid deterministic 3D Ray Launching is employed providing precise wireless channel characterization and hence, system level analysis of indoor scenarios. Coverage/capacity, interference mapping and time domain characterization estimations will be derived, considering different frequencies of operation below 6 GHz. The proposed methodology will be tested against a real measurement scenario, providing full flexibility and scalability for adoption in a wide range of IIoT capable environments.
Open Access
Implementation of context aware e-health environments based on social sensor networks
(MDPI, 2016) Aguirre Gallego, Erik; Led Ramos, Santiago; López Iturri, Peio; Azpilicueta Fernández de las Heras, Leyre; Serrano Arriezu, Luis Javier; Falcone Lanas, Francisco; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua
In this work, context aware scenarios applied to e-Health and m-Health in the framework of typical households (urban and rural) by means of deploying Social Sensors will be described. Interaction with end-users and social/medical staff is achieved using a multi-signal input/output device, capable of sensing and transmitting environmental, biomedical or activity signals and information with the aid of a combined Bluetooth and Mobile system platform. The devices, which play the role of Social Sensors, are implemented and tested in order to guarantee adequate service levels in terms of multiple signal processing tasks as well as robustness in relation with the use wireless transceivers and channel variability. Initial tests within a Living Lab environment have been performed in order to validate overall system operation. The results obtained show good acceptance of the proposed system both by end users as well as by medical and social staff, increasing interaction, reducing overall response time and social inclusion levels, with a compact and moderate cost solution that can readily be largely deployed.
Open Access
A 3D ray launching time-frequency channel modeling approach for UWB ranging applications
(IEEE, 2020) Otim, Timothy; López Iturri, Peio; Azpilicueta Fernández de las Heras, Leyre; Bahillo, Alfonso; Falcone Lanas, Francisco; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
Ultrawideband (UWB) has the ability to achieve decimetre level of ranging accuracy, hence, its wider usage nowadays in the field of positioning. In spite of the attractiveness of UWB, its performance is strongly dependent on the propagation channel. In this paper, an analysis of the the UWB channel for ranging applications using an inhouse developed 3D Ray launching (3D RL) algorithm is presented. A parametric study has been performed considering variations of cuboid size resolution of the simulation mesh, in order to analyze convergence impact on estimation accuracy, focusing on Radio frequency (RF) power levels as well as time domain characterization. The RF power results have been used to model the path-loss, small scale fading, and the power delay profile so as to obtain the statistics of the multipath channel as well as time of flight (TOF) estimation values. The results show that the 3D RL is a valuable tool to test UWB systems for ranging applications with a mean accuracy of up to 10 cm in multipath conditions considering complex scatterer distributions within the complete volume of the scenarios under test.
Open Access
Spatial V2X traffic density channel characterization for urban environments
(IEEE, 2021) Granda, Fausto; Azpilicueta Fernández de las Heras, Leyre; Celaya Echarri, Mikel; López Iturri, Peio; Vargas Rosales, César; Falcone Lanas, Francisco; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
In this work, Vehicle-to-everything (V2X) wireless communications performance is analyzed, in order to account for inherent scenario complexity, in the deployment phase of wireless systems towards the implementation of a Context Aware environment. An urban environment has been simulated by means of an in-house three-dimensional (3D) Ray Launching algorithm, coupled with a microscopic vehicular movement simulator, accounting for embedded urban elements as well as variable traffic densities within the complex environment. Large-scale and small-scale results are presented, as well as statistical analysis of the impact of different traffic densities. A campaign of measurements in the same real scenario has been performed, showing good agreement with wireless channel estimations for the considered frequency. These results can aid in V2X deployment configurations in urban environments, in order to minimize power consumption, optimize interference levels and increase overall system performance.
Open Access
Characterization and consideration of topological impact of wireless propagation in a commercial aircraft environment [wireless corner]
(IEEE, 2013) Rajo-Iglesias, Eva; Aguirre Gallego, Erik; López Iturri, Peio; Azpilicueta Fernández de las Heras, Leyre; Arpón Díaz-Aldagalán, Javier; Falcone Lanas, Francisco; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Wireless systems are gaining a relevant role for multiple communication tasks within commercial aircrafts. In this work, wireless propagation in an indoor commercial airplane cabin will be analyzed. The impact of indoor elements, such as passenger seats, luggage compartments and a dual deck structure will be considered, with the aid of in-house implemented 3D ray launching code. Multipath propagation plays a relevant role, given by the time domain characteristics obtained by spatially dependent power delay profiles and delay spread. The use of deterministic techniques in order to consider the inherent complexity of the airplane cabin can aid in wireless system planning in order to increase overall system capacity whilst reducing power consumption.
Open Access
Deterministic and empirical approach for millimeter-wave complex outdoor smart parking solution deployments
(MDPI, 2021) Rodríguez Corbo, Fidel Alejandro; Azpilicueta Fernández de las Heras, Leyre; Celaya Echarri, Mikel; López Iturri, Peio; Alejos, Ana V.; Shubair, Raed M.; Falcone Lanas, Francisco; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
The characterization of different vegetation/vehicle densities and their corresponding effects on large-scale channel parameters such as path loss can provide important information during the deployment of wireless communications systems under outdoor conditions. In this work, a deterministic analysis based on ray-launching (RL) simulation and empirical measurements for vehicle-to-infrastructure (V2I) communications for outdoor parking environments and smart parking solutions is presented. The study was carried out at a frequency of 28 GHz using directional antennas, with the transmitter raised above ground level under realistic use case conditions. Different radio channel impairments were weighed in, considering the progressive effect of first, the density of an incremental obstructed barrier of trees, and the effect of different parked vehicle densities within the parking lot. On the basis of these scenarios, large-scale parameters and temporal dispersion characteristics were obtained, and the effect of vegetation/vehicle density changes was assessed. The characterization of propagation impairments that different vegetation/vehicle densities can impose onto the wireless radio channel in the millimeter frequency range was performed. Finally, the results obtained in this research can aid communication deployment in outdoor parking conditions.
Open Access
Implementation of radiating elements for radiofrequency front-ends by screen-printing techniques for Internet of Things applications
(MDPI, 2019) Picallo Guembe, Imanol; Klaina, Hicham; López Iturri, Peio; Sánchez, Aitor; Méndez Giménez, Leire; Falcone Lanas, Francisco; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Gobierno de Navarra / Nafarroako Gobernua, 0011-1365-2017-000103
The advent of the Internet of Things (IoT) has led to embedding wireless transceivers into a wide range of devices, in order to implement context-aware scenarios, in which a massive amount of transceivers is foreseen. In this framework, cost-effective electronic and Radio Frequency (RF) front-end integration is desirable, in order to enable straightforward inclusion of communication capabilities within objects and devices in general. In this work, flexible antenna prototypes, based on screen-printing techniques, with conductive inks on flexible low-cost plastic substrates is proposed. Different parameters such as substrate/ink characteristics are considered, as well as variations in fabrication process or substrate angular deflection in device performance. Simulation and measurement results are presented, as well as system validation results in a real test environment in wireless sensor network communications. The results show the feasibility of using screen-printing antenna elements on flexible low-cost substrates, which can be embedded in a wide array of IoT scenarios.
Open Access
Deterministic propagation approach for millimeter-wave outdoor smart parking solution deployment
(MDPI, 2020) Rodríguez Corbo, Fidel Alejandro; Azpilicueta Fernández de las Heras, Leyre; Celaya Echarri, Mikel; López Iturri, Peio; Alejos, Ana V.; Falcone Lanas, Francisco; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Impact factor as an indicator of efficiency or sustainability is entirely correlated with the continuous development of the smart city concept technology application. Intelligent transportation systems (ITSs) and particularly autonomous vehicles are expected to play an important role in this challenging environment. Fast and secure connections will be pivotal in order to achieve this new vehicular communications’ application era. The use of millimeter-wave (mmWave) frequency range is the most promising approach to allow these real-time, high-demand applications that require higher bandwidth with the minimum possible latency. However, an in-depth mmWave-channel characterization of the environment is required for a proper mmWave-based solution deployment. In this work, a complete radio wave propagation channel characterization for a mmWave smart parking solution deployment in a complex outdoor environment was assessed at a 28 GHz frequency band. The considered scenario is a parking lot placed in an open free university campus area surrounded by inhomogeneous vegetation. The vehicle and vegetation density within the scenario, in terms of inherent transceivers density and communication impairments, leads to overall system operation challenges, given by multiple communication links operation at line-of-sight (LOS) and non-line-of-sight (NLOS) conditions. By means of an in-house developed 3D ray launching (3D-RL) algorithm, the impact of variable vegetation density is addressed, providing precise modelling estimations of large-scale multipath propagation effects in terms of received power levels and path loss. The obtained results along with the proposed simulation methodology can aid in an adequate characterization of an mmWave communication channel for new vehicular communications networks, applications, and deployments, considering the outdoor conditions as well as the impact of different vegetation densities, for current as well as for future wireless technologies.
Open Access
Performance analysis of ZigBee wireless networks for AAL through hybrid ray launching and collaborative filtering
(Hindawi, 2016) López Iturri, Peio; Casino, Fran; Aguirre Gallego, Erik; Azpilicueta Fernández de las Heras, Leyre; Falcone Lanas, Francisco; Solanas, Agustí; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica
This paper presents a novel hybrid simulation method based on the combination of an in-house developed 3D ray launching algorithm and a collaborative filtering (CF) technique, which will be used to analyze the performance of ZigBee-based wireless sensor networks (WSNs) to enable ambient assisted living (AAL). The combination of Low Definition results obtained by means of a deterministic ray launching method and the application of a CF technique leads to a drastic reduction of the time and computational cost required to obtain accurate simulation results. The paper also reports that this kind of AAL indoor complex scenario withmultiple wireless devices needs a thorough and personalized radioplanning analysis as radiopropagation has a strong dependence on the network topology and the specific morphology of the scenario. The wireless channel analysis performed by our hybrid method provides valuable insight into network design phases of complex wireless systems, typical in AAL-oriented environments.Thus, it results in optimizing network deployment, reducing overall interference levels, and increasing the overall system performance in terms of cost reduction, transmission rates, and energy efficiency.