# Cooperative Friendly Jamming Techniques for Drone-Based Mobile Secure Zone
## 5 Experiment
### Simulation
#### 5.1.2 Evaluation Environments  
The evaluation simulator was implemented using Octave v.6.1. The simulation was conducted in a PC environment with the Windows 10 operating system, 8 GB of RAM, and an Intel i5-7200U CPU. In the simulation, a free space of 200 m \(\times\) 200 m was formed, and the location of nodes was randomly arranged to prove the effectiveness of the CFJ-DMZ. The experimental environment was set as a free space that did not take into account the influence of air or other radio waves. In addition, the maximum transmission power of the transmitting node, receiving node, and friendly jamming drone in the simulation was 24 dBm each. We configured four experimental settings to measure the leaked amount of information according to the mobility of the device and the friendly jamming technique. Figure 4 shows each experimental configuration. After measuring the locations of the source node (S) and destination node (D), the locations of three drones (J) were calculated. The blue circles in Figure 4b,d represent the range in the cooperative jamming signals. A total of six eavesdropping nodes (eve1-6) were created, and the eavesdropping nodes (E) were located at arbitrary coordinates. The locations of the eavesdroppers were the same in all experiments for an effective comparison between the experiments. Table 2 shows a summary of the location of each node. In the simulation experiments, the distance from the source node to the destination source was set to 48.413 m in Figure 4a,b and to 2 m in Figure 4c,d. Figure 3: BER based on distance of Source-Eve and Drone-Eve. The test cases of the experimental settings in Figure 4 can be summarized as shown in Table 3. In the table, \"mobility\" refers to with or without movement of the source node. If the mobility is O, it indicates a case in which the source node sends information after moving to near the destination node. If the mobility is X, it indicates a case in which the source node sends information without moving to near the destination node. When the source node has mobility, and the distance between the source and destination nodes is close, the transmission signal strength of the source node is reduced. \"Friendly jamming\" refers to whether the friendly jamming technique of the drone is used. If friendly jamming \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Node**} & **Source in** & **Source in** & **Destiation** & **eve1** & **eve2** & **eve3** & **eve4** & **eve5** & **eve6** \\  & **Figure 4a,b** & **Figure 4c,d** & & & & & & & \\ \hline \multirow{2}{*}{Location} & (127.42, 60.1) & (102, 100) & (100, 100) & (23, 146) & (101, 125) & (155, 22) & (149, 89) & (73,71) & (101, 47) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Location of each node in simulation. Figure 4: Network configuration for CFJ-DMZ simulation: (**a**) None mobility and None friendly jamming, (**b**) None mobility and Friendly jamming, (**c**) Mobility and None friendly jamming, and proposed scheme (**d**) Mobility and Friendly jamming. is O, it indicates a case in which the drones transmit cooperative jamming signals when sending information. If it is X, it indicates a case in which friendly jamming signals are not transmitted. \"Source-Destination distance\" refers to the distance between the source and destination nodes. The CFJ-DMZ model corresponds to Figure 4d in which both mobility and friendly jamming occur. The design process of the simulation is as follows. First, it is assumed that there is a channel \(h_{sd}^{*}\) in the form of a complex conjugate between the source and destination nodes. It is also assumed that \(P_{s}\) at the transmitter and the receiver, and the maximum transmission power of \(P_{j}\) of the friendly jamming drones, are both 24 (dBm). Under these assumptions, the following equations are defined to measure the BER at each object.