analysis in Fig. 8.3. More specific details in relation to wireless signal variation as a function of transceiver location and surrounding environment can be seen by considering linear radial distributions of received power level in TX-RX links, shown in Fig. 8.4. I. Picallo et al. Vertical Planes x=168m Receiver power level path x=) 104m [dBm] [dBm] Y-axis (m) Y-axis (m) [dBm] Y-axis (m) Fig. 8.3 Estimation of distribution of received power levels for the UPNA campus scenario, considering frequencies of operation f@ 868 MHz, f@ 2.4 GHz, and f@ 3.5 GHz, for constant vertical planes at cut planes. The location for the cut planes is depicted schematically in the top image Different distributions are depicted in figure for all three frequencies of operation and considering two different link heights (i.e., h = 3.2 m and h = 8.7 m). The effects of fast fading can be clearly seen, with power dispersion in excess of 40 dB as a function of frequency and location, with a significant increase as the frequency of operation increases from 868 MHz to 3.5 GHz. It can be seen from the results obtained that an increase in the frequency of operation leads as expected to increased path losses and, hence, reduced coverage levels. Moreover, the presence of infrastructure elements of different types strongly influences coverage levels, owing to shadowing effects, penetration losses by propagating wave refraction, multipath propagation, diffraction effects on edges (e.g., buildings), and diffuse scattering effects (i.e., leaves in tree canopies or equivalent rough surfaces by non-uniform wall facades). This can be clearly seen in the case of multipath propagation, given by the large density of scattering elements within the scenario under analysis, leading to rich multipath components in time domain. In this sense, estimations of power delay profiles have also been obtained for the scenario and are depicted in Fig. 8.5. 8 Implementation of Context-Aware Environments with Massive IoT Systems h=3.2m h=3.2m h=8.7m h=8.7m Y-axis (m) Y-ax