**4. Conclusion**

This chapter presents a spectrum occupancy evaluation for two popular IoT communication standards, LoRa and Wi-Fi, based on extensive experiments. These include the change of the interfering nodes' number and their location in dense indoor placement. The implementation is realized using the PlutoSDR hardware platform. The 3D interference maps show that the effect of fading with distance on the same plane and in height is crucial in localizing interference-free areas in dense deployments where even with the wireless standards' mechanisms for multiple accesses, it is likely that some nodes and/or malicious users will create in-band interference. In the case of LoRa in the 868 MHz band, interference is a much more substantial issue, regardless of the interferers' number and proximity. As for Wi-Fi sensors, due to the much higher carrier frequency, the interference's influence may be reduced substantially even within the span of a couple of meters. Thus, algorithms for adaptive repositioning in 3D have the potential for improving the communications of indoor IoT networks, aside from or in concurrency with future dynamic access techniques such as volumetric spectrum sensing [26]. Such methods can also be extended with Deep Learningbased node identification for protection against physical layer attacks [27].
