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:

Research visit at UC Berkeley

Our lab member Alba Rozas has recently completed a PhD research visit at the Berkeley Wireless Research Center (BWRC), part of the University of California at Berkeley, under the supervision of renowned Profesor Jan Rabaey. This group carries out world-leading research in the fields of radio communications and wireless electronics, with a particular recent interest in Body Area Networks and the Human Intranet.

World Map with location pins for every BWRC member

The main research line of Alba’s PhD is focused on QoS-aware and energy efficient routing strategies for WSNs. This 5-month stay took place within the last stage of her PhD, and its main goal was the study and research of over-the-body communication aspects and the Human Intranet paradigm. These fields have unique characteristics that differentiate them from traditional WSNs, presenting new challenges and opportunities. Thus, in this research stay, Alba has focused on applying the core ideas of her PhD to the field of body area networks. As a result of the work carried out during the visit, she has ultimately developed an energy-efficient and QoS-aware strategy for on-body wireless communication, based on dynamic human activity detection.

In addition to this main research objective, the stay has also strengthened the already existing working relationship between BWRC and B105. Both labs are already collaborating in the development of health-related solutions and systems, initiated by Alvaro Araujo‘s two research visits at BWRC.

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.