# Behind the Door: Practical Parameterization of Propagation Parameters for IEEE 802.11 ad Use Cases
Their preliminary findings reveal that pedestrian movement generates a temporary reduction in signal-to-noise ratio (SNR) of more than 20 dB. In the domain of indoor propagation, our study investigates the impact of positioning an STA behind a door when an AP is situated in a hallway. Specifically, we examine how this transition from LOS to NLOS affects signal strength and potential power loss. Building on the investigation of indoor propagation challenges, previous studies have utilized ray-tracing simulations to assess channel characteristics [10]. For instance, reference [6] employed the knife-edge model to simulate pedestrian obstructions, while reference [5] presents a measurement-based spatio-temporal statistical channel model for short-range millimeter-wave links in large office rooms, malls, and station scenarios. These studies utilized ray-tracing techniques to account for first- and second-order reflections from various surfaces, inducing temporal channel fluctuations. The insights obtained from these investigations are invaluable for refining theoretical or simulation models. However, when considering duplicate fades, several assumptions are inherent. To enhance the accuracy of such simulations, our work contributes empirical channel parameters tailored to this specific context. Reference [7] presents the dynamic characteristics of the 60 GHz radio propagation channel through measurements conducted in an open-space office environment. Measurements aim to quantify the impact of natural human movements on path loss both before and during work hours, allowing for a comparison between dynamic scenarios and static conditions when the office is devoid of occupants. Using a vector network analyzer (VNA) with a 2 GHz bandwidth, they recorded a total of 9900 power loss measurements over 11 h for each receiver position. Five receiver positions were strategically chosen to examine three types of scenarios: LOS, obstructed line-of-sight (OLOS), and NLOS. From the data collected, the authors derived the loss of the channel path (PL), its probability density function (PDF), and its cumulative distribution function (CDF). In comparison, our method enhances current techniques by calculating the signal loss generated by walls and doors in office environments for similar height directional antennas. Moreover, in our work, we include the impact of those working inside workplaces who are not blocking the connection (i.e., sitting, doing their regular work), changing the multipath pattern. The authors in [11] provide an innovative on-air measurement setup for millimeter bands, explaining the derived parameters using a multi-probe anechoic chamber to emulate shadow fading generated by the human body. To examine the geometry of the paths, they employed ray tracing and image processing techniques. They concluded that shadow fades were influenced by the link's architecture, as well as the interaction between the multipath pattern and pedestrian trajectories. Our results expand previous studies by providing actual data from a real-world setting (outside the anechoic chamber) in which pedestrians move along a predetermined or random route. This is important not only for comparing outcomes but also for calibrating theoretical/ray-tracing simulation models to enhance accuracy. Based on the state of the art and existing comparisons and shortcomings, the goal of this work is to present an empirical measurement methodology and analyze the outcomes in both LOS and NLOS conditions, focusing on scenarios where an access point provides indoor stations compliant with the IEEE 802.11 ad standard. The proposed empirical approach aims to determine the additional power required to mitigate channel losses, ensuring adequate coverage and availability for user stations. Furthermore, we offer insights into the angular distribution of received power at the tested locations, serving as supplementary data to enhance understanding of the underlying physical processes.