Print Email Facebook Twitter Designing and implementing SFMAC: A MAC protocol for LoRa networks for efficient use of unlicensed bands Title Designing and implementing SFMAC: A MAC protocol for LoRa networks for efficient use of unlicensed bands Author Blanco Abad, Teresa (TU Delft Electrical Engineering, Mathematics and Computer Science) Contributor Venkatesha Prasad, Ranga Rao (mentor) KOUVELAS, N. (mentor) van Genderen, A.J. (graduation committee) Rao, Vijay (graduation committee) Degree granting institution Delft University of Technology Programme Electrical Engineering | Embedded Systems Date 2020-11-27 Abstract Long Range Wide Area Networks (LoRaWAN) offer easy deployment, robustness against interference, and operational longevity to energy constrained IoTdevices which communicate in a best-e_ort fashion in extended ranges. However, the simple (ALOHA-like) design of the MAC layer leads to packet collisions in dense LoRaWAN deployments with high traffic loads. To achieve scalability above a few hundreds of devices, time division is not an option, since LoRaWAN is asynchronous regarding communication. Further, feedback mechanisms are discouraged due to duty cycle limitations. In this document, we propose Spreading Factor MAC (SFMAC); a distributed and energy efficient MAC protocol for LoRaWAN, wherein {for the _rst time to the best of our knowledge{ high-SF channels are dedicated strictly to Channel Sensing (CS), while low-SF channels are focused on data-transmission. The Capture E_ect (CE) phenomena that is manifested in the PHY layer is extensively evaluated on-_eld and embodied in the SFMAC operating principle. The dedicated high-SF sensing allows e_ective revealing of hidden devices' transmissions without a_ecting the low-SF tra_c. We showcase the impact of SFMAC in scalability by designing a realistic implementation of the mechanism in ns-3. We report a x2.08 improvement in channel utilization and x2 goodput compared to LoRaWAN, without substantially increasing complexity. Subject Low Power Wide Area NetworksMAC protocolLoRa To reference this document use: http://resolver.tudelft.nl/uuid:95bd1d0a-af78-4ea0-8b20-bdf99e51c1c1 Embargo date 2023-11-26 Part of collection Student theses Document type master thesis Rights © 2020 Teresa Blanco Abad Files PDF Definitive_Msc_MariaTeres ... coAbad.pdf 4.05 MB Close viewer /islandora/object/uuid:95bd1d0a-af78-4ea0-8b20-bdf99e51c1c1/datastream/OBJ/view