Post-doctoral Research Visit F/m Downlink Optimization for Robust Direct-to-satellite Lorawan

Le descriptif de l’offre ci-dessous est en Anglais_ **Type de contrat**: CDD **Niveau de diplôme exigé**: Thèse ou équivalent **Fonction**: Post-Doctorant **Niveau d'expérience souhaité**: De 3 à 5 ans **A propos du centre ou de la direction fonctionnelle**: The Inria research centre in Lyon is the 9th Inria research centre, formally created in January 2022. It brings together approximately 320 people in 19 research teams and research support services. Its staff are distributed in Villeurbanne, Lyon Gerland, and Saint-Etienne. The Lyon centre is active in the fields of software, distributed and high-performance computing, embedded systems, quantum computing and privacy in the digital world, but also in digital health and computational biology. **Contexte et atouts du poste**: **About the centre** The postdoctoral position at Inria's AGORA research group, located at the La Doua Campus in Lyon, offers a unique opportunity to collaborate with esteemed experts such as Dr. Juan Fraire, Dr. Oana Iova, and Prof. Hervé Rivano. The appointee will use advanced software tools like FloRaSat, an Omnet++-based DtS-IoT simulator, enhancing their expertise in space communication systems and wireless sensor networks. This role is enriched by AGORA's strong international and academic-industrial collaborations. This position is a gateway to cutting-edge research and professional growth in IoT, space networking, and Internet technologies in general. **Context** Every year, Inria’s International Relations Department (DRI) has a few postdoctoral positions to support Inria's international collaborations. The postdoctoral contract will have a duration of 12 to 24 months. The default start date is November 1st, 2025, and not later than January 1st, 2026. One of the Inria Centres in France will recruit the postdoctoral fellow. Still, it is recommended that the time be shared between France and the partner country, in this case, the Universidade Federal de Santa Catarina in Brazil. Please note that the postdoctoral fellow has to start his/her contract in France and that the visits must respect Inria rules for missions. **Eligibility Conditions** **Mission confiée**: **Context** **Assignment** In the DtS-IoT context, the unique challenges associated with LoRaWAN’s downlink are multi-faceted. On the one hand, they involve the challenging selection of suitable downlinking gateways (situated onboard the LEO satellites) that minimize the number of transmissions to end devices with overlapping reception windows and coverage. On the other hand, once a LEO satellite is selected, intricate scheduling follows for each downlink packet to be forwarded across high-latency, low data rate, cross-linked, and multi-hop LEO networks to multiple LoRaWAN devices. Addressing these challenges requires developing specialized and customized solutions across several layers of the DtS-IoT network stack, physical layer models, MAC algorithms, network optimization, and satellite scheduling methods. The proposed solutions could be based on offline and online optimization and machine learning approaches to schedule downlink messages to prevent overlap, assure optimal channel conditions, and ensure seamless, reliable, and efficient communication between remote IoT devices and the space core network connected to the Internet. **Collaboration** Dr. Juan Fraire and Dr. Oana Iova actively collaborate with Prof. Richard Demo Souza from Universidade Federal de Santa Catarina (UFSC) in Brazil on the topic of Direct-to-Satellite Internet of Things convergence, also supported by a STIC AmSud project recently acquired by Inria and UFSC. **References** - Fraire, Juan A., Oana Iova, and Fabrice Valois. "Space-terrestrial integrated Internet of Things: Challenges and opportunities." IEEE Communications Magazine 60, no. 12 (2022): 64-70. - Fraire, Juan A., Pablo Madoery, Mehdi Ait Mesbah, Oana Iova, and Fabrice Valois. "Simulating lora-based direct-to-satellite IoT networks with FloraSat." In 2022 IEEE 23rd International Symposium on a World of Wireless, Mobile and Multimedia Networks (WoWMoM), pp. 464-470. IEEE, 2022. - Tondo, Felipe Augusto, Jean Michel de Souza Sant'Ana, Samuel Montejo-Sánchez, Onel Luis Alcaraz López, Sandra Céspedes, and Richard Demo Souza. "Non-Orthogonal Multiple-Access Strategies for Direct-to-Satellite IoT Networks." arXiv preprint arXiv:2409.02748 (2024). - Ron, Dara, Chan-Jae Lee, Kisong Lee, Hyun-Ho Choi, and Jung-Ryun Lee. "Performance analysis and optimization of downlink transmission in LoRaWAN class B mode." IEEE Internet of Things Journal 7, no. 8 (2020): 7836-7847. - Abboud, Samira, Nancy El Rachkidy, Alexandre Guitton, and Haidar Safa. "Gateway selection for downlink communication in LoRaWAN." In 2019 IEEE Wireless Communications and Networking Conference (WCNC), pp. 1-6. IEEE, 2019. **Principales activités**: - **Comprehensive Literature Review** - Survey state-of-the-art techniques in DtS-IoT, LoRaWAN downlink mechanism