## 4 Measurement Scenarios  
Propagation measurements were conducted on the passenger ferryboat, named Motor Ferry WAWEL (MF WAWEL), during mooring at the port quay. During the measurements, only the crew was present on the ferryboat. Structural elements of the environment (i.e., walls, ceiling, floor, doors, and handrails) are made of steel of various thicknesses. For all considered scenarios, the stationary RN was attached to the corridor wall at a height of 1.2 m, on the seventh passenger deck. A single MN was placed on the user moving along the axis of a narrow corridor. The separation between human skin and radiating elements was about 1 cm. The measurements were carried out by one user: a man with a height of 1.72 m, a weight of 60 kg and a body mass index (BMI) of 20.3. In Figure 2, a schematic diagram of the measurement equipment is shown. It illustrates the places where MN were mounted. From many possible mounting locations, three were selected as representative for WBANs applications, including smart watches, heart rate monitors, multimedia glasses, etc. [7; 23; 24]. These are:  
* right side of the head (HE\({}_{\text{R}}\)), with the height of \(h_{HE}\) = 1.65 m;
* chest (TO\({}_{\text{F}}\)), with the height of \(h_{TO}\) = 1.35 m; and
* left wrist (AB\({}_{\text{L}}\)), with the height of \(h_{AB}\) = 0.9 m.  
Typically, in other works [23; 24; 25], the distance between measurement points was calculated on the basis of the average speed of the user. This required continuous supervision during the measurements  
Figure 2: A schematic diagram of the measurement equipment. and manual determination of the beginning and the end of the measurement data recording process. During the presented research, RDM were performed by using the Symmetrical Double-Sided Two-Way Ranging (SDS-TWR) measurement method [26]. This allowed for the full automation of the system loss measurements. Time synchronization of both radio interfaces, using a dedicated signal line, allowed for obtaining the information on the system loss value and the corresponding distance between the receiver (Tx) and the receiver (Rx) at a given moment. Thus, all measurement data were recorded and analyzed regardless of the speed of the user in different phases of the scenario. It is known that static scenarios are characterized by a smaller spread of propagation attenuation around the mean value and a smaller error in distance estimation using RDMs due to the absence of the small-scale fading component associated with the user's body motion, or lack of changes of its position. For this reason, it was decided to analyze only dynamic scenarios, which are much more complex in terms of radio wave propagation [25; 27; 28]. The measurements were carried out for two dynamic scenarios (SCNs): approaching to (APR), and departing from (DEP), the RN. These two scenarios correspond to a typical human behavior in indoor environments, and they are widely considered in WBAN research. They allow for the analysis of the measurement data independently of the side of the body on which the node is located, i.e., regardless of the antenna's placement on the left or right wrist. For the DEP scenario, the user started the motion at the distance of 2 m from the RN with the line-of-sight (LOS) conditions and walked towards the end point through the L-shaped corridor. After 6.5 m along the walking path there is a change between the zone with LOS conditions and the zone behind the corridor's corner with non-LOS (NLOS) conditions. The walk ended after travelling a distance of 14 m. In Figure 3, a floor plan of the investigated environment, which is a part of the passenger ferryboat's seventh deck, is shown. The LOS and NLOS conditions were determined by the presence of the metallic walls between MN and RN. The APR scenario is reversed with respect to the DEP one, i.e., from the aspect of the walking direction and the starting and ending points of the route. For each scenario and MN placement, the measurements were repeated 20 times.