# Evaluation of Deployment Challenges of Wireless Sensor Networks at Signalized Intersections
## 5 Radioplanning Analysis  
The deployment of three different communication systems has been analyzed within the considered scenario. Firstly, an analysis of the received power and the receiver's sensitivity for the different technologies has been analyzed, leading to the most efficient coverage ratio for the deployment of the different systems. The first technology evaluated has been ZigBee technology. Specifically, the wireless devices used for simulation have been both, the XBee Pro and XBee motes from Digi International Inc. (Minnetonka, MN, USA). The main difference between them is the larger transmitter power of the XBee Pro, leading to longer range distance. In order to analyze the worst case conditions, the transmitted power levels considered has been reduced to the minimum default value. After that, the second technology evaluated has been Bluetooth, specifically Bluetooth Low Energy (BLE) and classic Bluetooth. BLE has been designed as a low-power solution for control and monitoring applications, in contrast with classic Bluetooth. Finally, the third technology evaluated has been the 802.11p radio, which is the standard to add wireless access in vehicular environments (WAVE). It must be pointed out that for this technology we have performed new simulations in the 5.9 GHz frequency. Three different modulations with three different data rates have been analyzed for the 802.11p radio standard. The transmitted power and sensitivity for the different communication systems considered is shown in Table 4.  
Figure 14: Comparison simulation vs. measurements for 2.41 GHz and 5.9 GHz in the scenario considered. Figure 15 shows the linear distributions of received power along the \(X\)-axis for different values of \(Y\) for different heights in the case of ZigBee and 802.11p radio and for 1.4 m height in the case of Bluetooth. In order to clarify which distribution lines are those represented in Figure 15 in the real scenario, the aerial view of these distribution lines are shown in Figure 16. It is observed that the distribution lines of received power, which corresponds with the transmitter antenna placed at the traffic light #1 are represented. These simulations results are shown in a bi-dimensional plane in Figure 5a. \begin{table}
\begin{tabular}{l l l l} \hline \hline  & \multicolumn{1}{c}{**Transmitted Power**} & \multicolumn{1}{c}{**Sensitivity**} \\ \hline
**ZigBee XBee Pro** & & 10 dBm & \(-\)100 dBm \\
**ZigBee XBee** & & 10 dBm & \(-\)92 dBm \\ \hline \multirow{2}{*}{**BLE**} & **Minimum Transmitted Power** & \(-\)20 dBm & \(-\)93 dBm \\  & **Maximum Transmitted Power** & 10 dBm & \(-\)87 dBm \\ \hline
**Bluetooth Class 1** & & 20 dBm & \(-\)90 dBm \\
**Bluetooth Class 2** & & 4 dBm & \(-\)90 dBm \\
**Bluetooth Class 3** & & 0 dBm & \(-\)90 dBm \\ \hline \multirow{2}{*}{**802.11p**} & **BPSK-3 Mbps** & 24 dBm & \(-\)95 dBm \\  & **16 QAM-18 Mbps** & 24 dBm & \(-\)83 dBm \\  & **64 QAM-27 Mbps** & 21 dBm & \(-\)77 dBm \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Parameters for the different considered wireless communication systems. Figure 15: _Cont._  
Figure 15a,b shows the comparison between the received power of XBee Pro and XBee with the sensitivity of each of them. Figure 15c shows the comparison between BLE with the maximum and minimum transmitted power and the higher and lower receiver sensitivity depending of which type of BLE has being used. Figure 15d shows the comparison between Class 1, Class 2, and Class 3 of classic Bluetooth. Figure 15e,f shows the comparison between different devices with different modulations and data rates of the 802.11p standard, for different values of \(Y\). It can be seen that there are some points where the signal goes down below the sensitivity level. The comparison of the linear distribution of received power along the X-axis and \(Y\)-axis for different lines in the considered scenario with the different sensitivity levels, leads to radio planning engineers to know the radio coverage of the different systems.