Afhamisis M., Stumpf D., Palattella M.R., Conti M.
2026 IEEE International Conference on Communications Workshops Icc Workshops 2026 Proceedings, 2026
Non-terrestrial networks (NTN) are a key enabler for extending massive Internet of Things (IoT) connectivity beyond the coverage of terrestrial infrastructure. Supporting a large number of low-power and sporadically active devices over satellite links requires scalable and energy-efficient access mechanisms. Investigating and optimizing such mechanisms, as well as evaluating new architectures and protocol designs, requires flexible and realistic experimental environments. In this paper, we present SIMON, a satellite IoT testbed designed to support the evaluation of different scenarios and optimization techniques for NTN IoT systems. Among various IoT technologies, LoRaWAN is selected and implemented as a representative low-power wide-area solution, while the testbed architecture is designed to be extensible to other IoT technologies. SIMON integrates two complementary emulation environments for the satellite backhaul link: a hardware-based emulator and a software-based emulator, enabling controlled experimentation under diverse network, channel, and weather conditions. To demonstrate the effectiveness of the proposed testbed, we implement and evaluate two methods proposed in our prior work: SALSA, a satellite-aware transmission scheduling mechanism that assigns collision-free uplink timeslots based on predicted satellite visibility, and REACT, a lightweight application-layer time-synchronization method providing a time reference for devices. Experimental results show that SIMON provides a reliable and efficient platform for validating access optimization and synchronization mechanisms in NTN-IoT systems, and can serve as a flexible experimental framework for future satellite IoT technologies.
