# Deterministic Propagation Modeling for Intelligent Vehicle Communication in Smart Cities
## 2 Materials and Methods
### Experimental Measurements  
To complement the radio wave characterization assessment with network parameter analysis for V2V and V2I communication links, a set of experimental measurements have been developed in the same urban scenario. V2V and V2I communication links for four different configurations have been analyzed: V2V with the vehicles on the same and opposite sides, and V2I with the vehicle and infrastructure in the same and opposite sides. Figure 2 shows with a blue diamond the vehicles considered for the experiments, and with a red circle the location of the infrastructure (streetlight) located faced between them. The different communications links analyzed in the experiments are shown in Figure 2 (right). Figure 3 presents the vehicles involved in the experimentation re-marked in yellow (a, b, c and e), while the antenna fixed on the infrastructure is re-marked in red (d). Figure 3a-c show the traffic on the north east side of the avenue and the location of the three vehicles used for the experimentation. Figure 3d shows the antenna fixed to the streetlight which is connected to an Ubiquitin XtremeRange5 card placed into the vehicle and powered by its battery. Figure 3e shows that vehicles, trees, garbage containers and pedestrians coexist in the working scenario. \begin{table}
\begin{tabular}{c c} \hline \hline
**Parameters** & **Values** \\ \hline
**TX1, TX2**: & \\ P\({}_{\text{t}}\) */Gain(G\({}_{\text{t}}\))/Frequency/Height/ & 0 dBm/0 dB/5.9 Ghz/3.5 m \\ polarization. & omnidirectional. \\ \hline
**RX**: RST **/Gain(G\({}_{\text{r}}\))/Frequency/Height. & \(-\)100 dBm/0 dB/5.9 Ghz/1.5 m \\ /polarization. & omnidirectional. \\ \hline
**3D-RL**: horizontal and vertical angular resolution & \(\pi\)/180 rad \\ Angular resolution of diffracted rays. & \(\pi\)/20 rad \\ Maximum permitted reflections. & 7 hops \\ Cuboid segmentation for analysis. & 1 m\({}^{3}\) (1 \(\times\) 1 \(\times\) 1) m \\ \hline
**Scenario**: dimension. & (400 \(\times\) 150 \(\times\) 22) m \\ \hline \hline \end{tabular}  
* P*: Power transmitted, RST ** (Received Signal Threshold).  
\end{table} 
Table 2: Simulation parameters. The hardware used in the experiments has been two RB433 UAH MikroTik (MikroTik, Riga, Latvia) devices where two Ubiquitin XtremeRange cards (for 2.4 and 5 Ghz communication, respectively) are connected to each device (see Figure 4). The RB433 device is a 680 MHz CPU (AR7161) miniPC, with 128 MB of RAM, 3 miniPCI slots, a serial port and Openwrt as operating system. Power supply is provided to the RB433 device by a 12 Volt DC vehicle car cigarette lighter power adapter and an AC/DC inverter. Although each RB433 device can use both 2.4 and 5.9 Ghz communication frequencies, due to the Ubiquitin XtremeRange2 (2.4 Ghz) and XtremeRange5 (5.9 Ghz) cards, in this work we have just considered the 5.9 Ghz band of the IEEE 802.11a standard. The average power consumption of the Ubiquitin XtremeRange5 card on transmission is 28 dBm. Antennas are magnetized allowing then to be fixed easily to both a vehicle roof and streetlights. Since the vehicles used for the experiment have energy-saving mechanisms, it has been necessary to keep the vehicle engines running during the experiment to ensure the uninterrupted power supply to the RB433. Figure 3: Working scenario: (a–c) location of the vehicles used for the experimentation remarked in yellow; (d) antenna fixed in the infrastructure remarked in red; (e) working scenario. Figure 2: Location of vehicles, infrastructures, V2V and V2I communications links: real scenario (**left**) and schematic simulation scenario (**right**). Communications are analyzed by means of _iperf_ (Iperf2, [[http://sourceforge.net/projects/iperf2](http://sourceforge.net/projects/iperf2)]([http://sourceforge.net/projects/iperf2](http://sourceforge.net/projects/iperf2))), which is a widely used tool that allows measurement of network performance metrics such as throughput, packet loss and jitter.