## 6 Experiments  
The experiments were confirmed for the effectivity of the prototype AAA system and the DTN routing in the proposed winter road surveillance system. First of all, the beamforming angle by the given voltages experimented in the anechoic chamber room in Fukuoka Institute of Technology, Japan. In the experiments, the antenna was fixed on the rotatable table, and the differences of the given voltages for each antenna elements were 0, 5, 10, and 15 V. The experimented radio wave was IEEE802.11b (DSSS, 2.4 GHz). Figure 9 shows the results of the RSSI levels by the given voltage. The results show that the beam-forming angle in the prototype system was properly confirmed by the differences of the given voltage in the antenna elements. Therefore, if the proposed methods can estimate the angle to the target vehicle, it is considered that the longer radio connections can be realized. Secondly, the quickness of the image recognition and the beam-forming controls were evaluated by the prototype system. In the experiment, the printed picture of the vehicle was previously prepared, and Figure 10 shows the experimental circumstances in Uchida Lab, Fukuoka Institute of Technology, Japan. The A4 size printed red vehicle was fixed at a distance \(d=0.5\) m from the camera, and the captured images were used for the calculation of the distance and the angle to the vehicle in the note PC. Then, after calculation of the Kalman filter, the proper voltage was remotely set to the voltage meter through the LAN in the prototype system. Further, the printed vehicle in the picture was slightly moved to the points of \(\theta=0\), 5, 10, 15, 20, 25, and 30 degrees by manual controls, and the target voltage to the voltage meter was calculated in the experiments. Table 1 shows the results of the experiments. Figure 10: The experimental circumstances in the experiments. Figure 9: The results of RSSI by the voltage differentials in each antenna element with the prototype system. The results show the beam-forming controls were confirmed within one second, and it is assumed that the proposed methods are effective for the rapid controls for the V2V communication. Moreover, it is considered that the parameters in the Kalman filter calculation can deal with the durations for the beam-forming and that these adjustments will be the future works in this study. Finally, these results are introduced to the network simulator in order to evaluate the effectivity of the proposed methods in the actual fields. The ONE simulator [23; 24] was used for the basic frameworks for the implementations, and the 10 km \(\times\) 10 km GIS map of Takizawa City in Japan was introduced into the simulator, as shown in Figure 11.  
The data delivery rate and the latency from Takazawa City Office to Iwate Prefectural University was experimented upon under the different number of the vehicles in the simulation, and the nondirectional antenna with IEEE802.11b and the proposed AAA system with IEEE802.11b were compared in terms of effectiveness in the experiments. In the experiments, the duration of the data connection was set as five seconds for the nondirectional antenna group. That is because it takes about five seconds to set the DHCP configuration in the previous experiments. Further, the duration of the processing time was set one second from the experiments as mentioned regarding beam-forming in the previous section. Then, the wireless connection by the MAC address and Android ID was confirmed by the implementations of the previous paper [25]. Table 2 shows the major scenario in the modified simulator. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Angle (Degree)** & **Processing Time (s)** & **Observed Voltage (V)** \\ \hline
5 & 0.733 & 4.99 \\
10 & 0.843 & 9.99 \\
15 & 0.918 & 15.00 \\
20 & 0.937 & 20.00 \\
25 & 0.953 & 24.99 \\
30 & 0.965 & 29.99 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Results of the beam-forming controls by the prototype system.