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.
Open Access
Design and experimental validation of a LoRaWAN fog computing based architecture for IoT enabled smart campus applications
(MDPI, 2019) Fraga Lamas, Paula; Celaya Echarri, Mikel; López Iturri, Peio; Castedo, Luis; Azpilicueta Fernández de las Heras, Leyre; Aguirre Gallego, Erik; Suárez Albela, Manuel; Falcone Lanas, Francisco; Fernández Caramés, Tiago M.; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
A smart campus is an intelligent infrastructure where smart sensors and actuators collaborate to collect information and interact with the machines, tools, and users of a university campus. As in a smart city, a smart campus represents a challenging scenario for Internet of Things (IoT) networks, especially in terms of cost, coverage, availability, latency, power consumption, and scalability. The technologies employed so far to cope with such a scenario are not yet able to manage simultaneously all the previously mentioned demanding requirements. Nevertheless, recent paradigms such as fog computing, which extends cloud computing to the edge of a network, make possible low-latency and location-aware IoT applications. Moreover, technologies such as Low-Power Wide-Area Networks (LPWANs) have emerged as a promising solution to provide low-cost and low-power consumption connectivity to nodes spread throughout a wide area. Specifically, the Long-Range Wide-Area Network (LoRaWAN) standard is one of the most recent developments, receiving attention both from industry and academia. In this article, the use of a LoRaWAN fog computing-based architecture is proposed for providing connectivity to IoT nodes deployed in a campus of the University of A Coruña (UDC), Spain. To validate the proposed system, the smart campus has been recreated realistically through an in-house developed 3D Ray-Launching radio-planning simulator that is able to take into consideration even small details, such as traffic lights, vehicles, people, buildings, urban furniture, or vegetation. The developed tool can provide accurate radio propagation estimations within the smart campus scenario in terms of coverage, capacity, and energy efficiency of the network. The results obtained with the planning simulator can then be compared with empirical measurements to assess the operating conditions and the system accuracy. Specifically, this article presents experiments that show the accurate results obtained by the planning simulator in the largest scenario ever built for it (a campus that covers an area of 26,000 m2), which are corroborated with empirical measurements. Then, how the tool can be used to design the deployment of LoRaWAN infrastructure for three smart campus outdoor applications is explained: a mobility pattern detection system, a smart irrigation solution, and a smart traffic-monitoring deployment. Consequently, the presented results provide guidelines to smart campus designers and developers, and for easing LoRaWAN network deployment and research in other smart campuses and large environments such as smart cities.
Open Access
Análisis topológico de redes de sensores inalámbricos en entornos interiores complejos
(2011) López Iturri, Peio; Falcone Lanas, Francisco; Fernández Valdivielso, Carlos; 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
El objetivo de este proyecto fin de carrera es analizar el impacto de entornos interiores complejos en el despliegue de infraestructuras de redes de sensores inalámbricos. Concretamente, la influencia en los valores de RSSI, consumo de energía y PER (Packet Error Ratio) serán los datos más significativos en el estudio. Se analizará especialmente la influencia de la topología y morfología de la red en varios escenarios interiores complejos mediante simulaciones basadas en el método de trazado de rayos 3D y mediante medidas reales hechas directamente con los dispositivos inalámbricos ubicados en dichos escenarios. Teniendo en cuenta el rápido incremento de las aplicaciones en las que estas redes son esenciales (monitorización de hábitats, monitorización de infraestructuras, asistencia sanitaria, domótica, defensa, agricultura, ganadería, etc.), entender su comportamiento en un escenario real es imprescindible para un adecuado y eficiente despliegue de las mismas. Todas las redes y dispositivos analizados en este trabajo están basados en la norma IEEE 802.15.4. Esta norma, en la que el estándar basado en ella más conocido y utilizado es ZigBee, trata sobre las LR-PANs (Low Rate Personal Area Network), las cuales se caracterizan por estar los dispositivos alimentados por baterías. Encontrar la mejor configuración y distribución espacial de los dispositivos que forman la red de sensores, de tal forma que el consumo de energía sea el menor posible, será uno de los objetivos más importantes, ya que esto significaría alargar al máximo la vida de las baterías. Más teniendo en cuenta que las redes de sensores pueden contener varios centenares o millares de dispositivos. De igual forma, se mejoraría el impacto medioambiental.
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.
Open Access
Design and performance analysis of wireless body area networks in complex indoor e-Health hospital environments for patient remote monitoring
(SAGE, 2016) Aguirre Gallego, Erik; López Iturri, Peio; Azpilicueta Fernández de las Heras, Leyre; Rivarés Garasa, Carmen; 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 article, the design and performance analysis of wireless body area network–based systems for the transmission of medical information readable in an android-based application deployed within complex indoor e-Health scenarios is presented. The scenario under analysis is an emergency room area, where a patient is being monitored remotely with the aid of wearable wireless sensors placed at different body locations. Due to the advent of Internet of Things, in the near future a cloud of a vast number of wireless devices will be operating at the same time, potentially interfering one another. Ensuring good performance of the deployed wireless networks in this kind of environment is mandatory and obtaining accurate radio propagation estimations by means of a computationally efficient algorithm is a key issue. For that purpose, an in-house three-dimensional ray launching algorithm is employed, which provides radio frequency power distribution values, power delay profiles, and delay spread values for the complete volume of complex indoor scenarios. Using this information together with signal-to-noise estimations and link budget calculations, the most suitable wireless body area network technology for this context is chosen. Additionally, an in-house developed human body model has been developed in order to model the impact of the presence of monitored patients. A campaign of measurements has been carried out in order to validate the obtained simulation results. Both the measurements and simulation results illustrate the strong influence of the presented scenario on the overall performance of the wireless body area networks: losses due to material absorption and the strong influence of multipath components due to the great number of obstacles and the presence of persons make the use of the presented method very useful. Finally, an android-based application for the monitoring of patients is presented and tested within the emergency room scenario, providing a flexible solution to increase interactivity in health service provision.
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
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
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
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.