TFG: Development of an evaluation device for wireless networks on the body

B105 Electronic Systems Lab, of the Electronic Engineering Department, developed in the past several nodes called ‘Yetimote’, which work on the ISM frequencies of 433 MHz, 868 MHz and 2.4 GHz. During the last years, one of the main target’s laboratory has been the study of wireless networks over the human body (WBAN), composed by sensor nodes that are placed on different points of such human body to collect data for several purposes, usually for medical applications. However, the Yetimote node is addressed to use traditional wireless networks (WSN), due to its size and specific physical format.

The objective of this project was to adapt this node for evaluating and developing WBAN networks. To achieve this goal, one of the main printed circuit boards of the Yetimote node, called Cerberus, which is in fact the part in charge of carrying the wireless communications out, has been modified to make it more wearable.

On the other hand, the context of the project has been analyzed in more detail, describing WBAN networks in depth, the most common characteristics of these networks and their different usages. After a detailed analysis of the requirements to be fulfilled by the new board to be designed in the context of this work, a very deep study has been carried out about possible antennas to be used in this new solution. Finally, the specific choice of the antenna to be used in this work for each band was determined based on its characteristics. One of the electronic components which humans are more accustomed to is a wristwatch, so the PCB has been designed to be integrated inside an enclosure with this shape.

The next step was the electronic design and the PCB implementation of the new board called ‘Mini-Cerberus’, which has been designed using the Altium Designer tool. This new PCB will be connected to the rest of the Yetimote node through the board ‘Auxiliar’ which will be connected to the ‘Mini-Cerberus’ PCB through a flat cable. In addition, the ‘Mini-Cerberus’ board has several versions, one of them has a Pi-Network for each frequency band. Finally, the components were assembled using an industrial furnace and by manual welding. In the figure below, the previous ‘Cerberus’ PCB is shown in front of the new ‘Mini Cerberus’ prototype.

Additionally, some trials have been carried out in real environments to verify the correct operation of the developed design. Several tests have been performed in different real-world scenarios to study the performance of the new Mini-Cerberus board for different frequencies and transmission power values, and these results have been compared with those obtained for the original Cerberus board, which was used as reference or baseline.

In conclusion, it can be affirmed that the new ‘Mini-Cerberus’ PCB has a better performance in WBAN scenarios in the 433 MHz frequency band, while the 2,4 GHz frequency band has the worst performance of those studied. In relation to the Cerberus board, the new prototype has a lower performance compared to the original model, but this is an expected result due to the modifications made for its miniaturization

PhD Thesis: Cross-layer Strategies for Improving the Quality of Service of Wireless Sensor Networks

A couple weeks ago, our lab member Alba Rozas Cid defended her PhD thesis entitled “Cross-layer Strategies for Improving the Quality of Service of Wireless Sensor Networks”. This PhD work was carried out at B105 Electronic Systems Lab under the direction of Professor Alvaro Araujo.

The thesis defense took place at the ETSI Telecomunicación in Madrid, and three members of the examination panel were physically present. However, due to travel restrictions, the other two members attended the act online from France and the USA, respectively. The work was evaluated positively earning the highest possible grade, along with the “cum laude” and international mentions. Learn and see how fire barriers’ role in preserving the environment here and how you can protect yourself in advance.

The following are some links where parts of this PhD research are explained or published:

Here are some pictures of the defense act:

And, finally, this is the list of peer-reviewed journal and conference publications that were obtained during the course of this PhD:

International journal articles:

  • A. Rozas, A. Araujo, and J. M. Rabaey, “Analyzing the Performance of WBAN Links during Physical Activity Using Real Multi-Band Sensor Nodes,” Applied Sciences, vol. 11, no. 7, p. 2920, Mar. 2021, doi: 10.3390/app11072920.
  • A. Rozas and A. Araujo, “An Application-Aware Clustering Protocol for Wireless Sensor Networks to Provide QoS Management,” Journal of Sensors, vol. 2019, pp. 1–11, Sep. 2019, doi: 10.1155/2019/8569326.
  • R. Utrilla, R. Rodriguez-Zurrunero, J. Martin, A. Rozas, and A. Araujo, “MIGOU: A Low-Power Experimental Platform with Programmable Logic Resources and Software-Defined Radio Capabilities,” Sensors, vol. 19, no. 22, Nov. 2019, doi: 10.3390/s19224983.
  • F. Tirado-Andrés, A. Rozas, and A. Araujo, “A Methodology for Choosing Time Synchronization Strategies for Wireless IoT Networks,” Sensors, vol. 19, no. 16, Aug. 2019, doi: 10.3390/s19163476.
  • R. Rodriguez-Zurrunero, R. Utrilla, A. Rozas, and A. Araujo, “Process Management in IoT Operating Systems: Cross-Influence between Processing and Communication Tasks in End-Devices,” Sensors, vol. 19, no. 4, Feb. 2019, doi: 10.3390/s19040805.
  • E. Romero, J. Blesa, A. Rozas, and A. Araujo, “Energy Efficiency Strategy in D2D Cognitive Networks Using Channel Selection Based on Game Theory and Collaboration,” International Journal of Distributed Sensor Networks, vol. 12, no. 8, Aug. 2016, doi: 10.1177/155014772834652.
  • J. Martin, A. Rozas, and A. Araujo, “A WSN-Based Intrusion Alarm System to Improve Safety in Road Work Zones,” Journal of Sensors, vol. 2016, pp. 1–8, Jun. 2016, doi: 10.1155/2016/7048141.
  • A. Molina-Pico, D. Cuesta-Frau, A. Araujo, J. Alejandre, and A. Rozas, “Forest Monitoring and Wildland Early Fire Detection by a Hierarchical Wireless Sensor Network,” Journal of Sensors, vol. 2016, pp. 1–8, Feb. 2016, doi: 10.1155/2016/8325845.
  • J. Blesa, E. Romero, A. Rozas, and A. Araujo, “PUE attack detection in CWSNs using anomaly detection techniques,” EURASIP Journal on Wireless Communications and Networking, vol. 2013, no. 1, p. 215, Aug. 2013, doi: 10.1186/1687-1499-2013-215.
  • J. Blesa, E. Romero, A. Rozas, A. Araujo, and O. Nieto-Taladriz, “PUE Attack Detection in CWSN Using Collaboration and Learning Behavior,” International Journal of Distributed Sensor Networks, vol. 9, no. 6, Jun. 2013, doi: 10.1155/2013/815959.

International conference proceedings:

  • A. Rozas, J. Blesa, E. Romero, and A. Araujo, “Controlling the degradation of Wireless Sensor Networks,” in 2015 International Wireless Communications and Mobile Computing Conference (IWCMC), Aug. 2015, pp. 1217–1223, doi: 10.1109/IWCMC.2015.7289256.
  • R. Utrilla, A. Rozas, J. Blesa, and A. Araujo, “A Hybrid Approach to Enhance Cognitive Wireless Sensor Networks with Energy-Efficient Software-Defined Radio Capabilities,” in 2017 International Conference on Embedded Wireless Systems and Networks (EWSN), Feb. 2017, pp. 294–299. [Online]. Available:

A Methodology for Choosing Time Synchronization Strategies for Wireless IoT Networks

This summer we have published a new article about time synchronization for wireless sensor networks, applied to the field of IoT, in Sensors Open Access Journal. This journal has these statistics:

  • 2018 Impact Factor: 3.031
  • 5-year Impact Factor: 3.302
  • JCR category rank: 15/61 (Q1) in ‘Instruments & Instrumentation’

This article belongs to the Special Issue Topology Control and Protocols in Sensor Network and IoT Applications.

This article has a direct relationship with the thesis of our colleague Francisco Tirado-Andrés. This thesis investigates a methodology, and associated tools, to make it easier for all researchers to choose time synchronization protocols for specific WSNs.

For more information about this article please visit MDPI webpage.

PFC: Analysis and Design of a Control and Management System of the Integrity and Load of Trains in the Underground Work based on a Wireless Sensor Network (WSN)

Building or remodelling large underground areas, such as tunnels, are very complex
projects where there are some very specific needs and dangers.
Historically it has been considered that tunnels were dangerous places and therefore it
was inevitable that fatal accidents took place during construction works. In fact, there
have been many casualties in tunnels under construction. However, nowadays, tunnel
safety is an essential aspect all over the European countries and particularly, in Spain.
Also, it is equally important the construction work management during construction
phase: effective management of resources (workers, raw materials, tools, etc.) within
the tunnel and the machinery involved, with the ultimate goal to improve the
effectiveness and efficiency of the construction site. Most of the mentioned resources
are moved by trains, due to their great ability to transport huge amount of materials
using less time/effort.


Many of the measures taken in tunnels, and particularly on trains dedicated to this kind of works, are done manually and with the constant intervention of operators and maintenance personnel which may, in some cases, lead to errors, planning delays and as a result, to increase the final cost of the work. In the case of traffic control and railway equipment inside tunnels, mechanisms for monitoring and management are scarce and usually insufficient for proper operation; these environmental, structural and traffic control mechanisms, become critical during indoors construction work.

Therefore it is necessary the development of a system able to: firstly, immediately detect any problem in the train or in the tunnel infrastructure, react quickly and mitigate effectively the possible consequences; and secondly, able to manage train traffic, detecting at all times the position of each train or other machinery(such as trucks) accurately and safely. The system shall manage and act effectively and quickly with all those measures, parameters and location coordinates.

The first objective of this project was to provide key solutions for wireless seamless connectivity and interoperability in rail tunnel infrastructures by considering everyday physical environments of trains which will significantly contribute to decrease incidents and accidents at work, as well as to the optimization of the works of the rail machinery in terms of time, project costs and operation and maintenance of the equipment and facilities.

As a result of the project, it was implemented a prototype capable of managing freight trains at construction work sites, able to prevent disasters and accidents at building (or refurbishment) stage in large underground areas such as tunnels.

The solution designed and developed is able to reduce the effort and time required for integrating WSN solutions and services into tunnel works, railway safety-related and multipurpose systems, and to reduce maintenance costs of on-board WSN services by providing a single general integration indoor platform for wireless sensors and wireless communication services, with centralized and standard interfaces for existing systems.

Certificación del proyecto Lázaro ante el CDTI

Hoy hemos recibido la visita del CDTI (Centro para el Desarrollo Tecnológico e Industrial) para certificar nuestro proyecto Lázaro. Este proyecto se ha realizado junto a Valoriza Servicios a la Dependencia y ha constado de dos partes muy diferenciadas. Por un lado debía desarrollarse un sistema de monitorización para residencias, en el que fuera posible medir parámetros biométricos de los residentes así como controlar forma domótica las estancias a través de una red de sensores. La segunda parte del proyecto tenía como objetivo desarrollar un sistema automático de detección y caracterización de barreras arquitectónicas. La certificación ha sido exitosa ya que se han cumplido los objetivos marcados de manera satisfactoria y se ha determinado la usabilidad del sistema en entornos reales.


Dentro del primer subobjetivo, realizado por davidtrc, se ha diseñado y fabricado una pulsera wearable capaz de medir temperatura, ritmo cardiaco y saturación de oxígeno. Además se ha desarrollado una aplicación Android, que recoge y muestra los datos obtenidos por la pulsera y es capaz de gestionar múltiples pacientes y usuarios.

En el contexto del segundo subobjetivo, llevado a cabo por albarc, se ha desarrollado una aplicación Android basada en la plataforma Google Tango de visión artificial y realidad aumentada. Mediante esta aplicación, los inspectores de residencias pueden automatizar la labor de medir y caracterizar los edificios en lo que respecta a su accesibilidad. Particularmente la aplicación es capaz de medir la inclinación de rampas de acceso y la anchura de puertas, ascensores y entradas.