Christos Giachoudis will defend his PhD thesis entitled “PHY and MAC Layer Considerations and Coverage Enhancement for Medical Optical Wireless Body-Area Networks” on Thursday, August 27, 2026, at 02:00 P.M. in room Pierre Cotton, at Institut Fresnel, campus St Jérôme, Marseille.
The presentation & slides will be in English. A link to join the defense online will be provided at a later date.
Jury Composition :
– Laurent ROS, Gipsa-lab, Université Grenoble Alpes, Président of the Jury
– Eric SIMON, IEMN, Université de Lille, Reviewer
– Pierre COMBEAU, XLIM, Université de Poitiers, Reviewer
– Beatriz ORTEGA, PRL, Université Polytechnique de Valence, Espagne, Examiner
– George KARAGIANNIDIS, Dépt. ECE, Université Aristote de Thessalonique, Grèce, Examiner
– Zabih GHASSEMLOOY, OCRG, Université Northumbria Newcastle, Royaume-Uni, Examiner
– Mohammad-Ali KHALIGHI, Institut Fresnel, École Centrale Méditerranée, Thesis Director
– Stanislav ZVANOVEC, Université Technique Tchèque, Prague, République Tchèque, Thesis Co-Director
Abstract : Global healthcare systems are currently facing a critical shortage of medical professionals, a challenge exacerbated by aging populations and the rising demand for continuous health monitoring. While remote patient monitoring using Wireless Body Area Networks (WBANs) offers a viable solution to mitigate this pressure, traditional Radio Frequency based systems suffer from spectrum congestion, interference, and security vulnerabilities. In this thesis, we investigate the implementation of Optical Wireless Communications (OWCs), as a robust, secure, and interference-free alternative for the next generation of medical WBANs. We focus on three pivotal areas of the network design process: the Physical (PHY) layer, the Medium Access Control (MAC) layer, and coverage-enhancing technologies. In the PHY Layer, to address the performance degradation due to Baseline Wander, inherent in optical systems using pulsed modulation, we consider the well-established line-coding techniques of Manchester and 8B10B coding. Through numerical simulations and experiments, we demonstrate that Manchester coding is a suitable low-complexity solution for relatively low-data rate, pulse-modulated optical transmissions, e.g., in the case of medical WBANs.
Concerning the MAC Layer, we first explore energy-efficient scheduling schemes for data transmission in the network. Focusing on the contention-based Slotted-ALOHA protocol, we propose a network optimization approach based on the Particle Swarm Optimization (PSO). Then we provide a comparative analysis of two different protocols, i.e., Time Division Multiple Access (TDMA) and Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA), where we identify the TDMA as a high-performance solution for maintaining Quality-of-Service and minimizing energy consumption. Finally, to overcome the Line-of-Sight limitations and signal directivity of OWC, we propose the integration of Reconfigurable Intelligent Surfaces (RIS) into optical WBANs, and analyze their benefit in improving the link reliability and energy consumption. The results demonstrate that RIS can significantly enhance network coverage and expand battery operated network nodes’ lifetime. Conducted within the framework of the EU-funded OWIN6G project, this research provides design insights and practical solutions to facilitate the widespread adoption of optical WBANs, contributing to the evolution of efficient and reliable healthcare monitoring in the 6G era.
