## 2 Public Safety Network
### Drones for Public Safety  
Drones can fly autonomously in the sky and are associated with different applications in civilian tasks such as transportation, communication, agriculture, disaster mitigation, emergency response, smart things, and environmental preservation. They are a promising technology because of their rapid and easy deployment, ability to dynamically change location in an emergency situation, quick reconfiguration, and flexible technology. Furthermore, they can provide effective communication for a public safety network, as shown in Figure 2. Moreover, drones can move around to provide large disaster coverage area faster, and achieve ubiquitous connectivity within a minimum time in a public safety network. Emergency communications are the most important and specialized field for giving high value to people's lives. During an earthquake or tsunami, there is no ground transportation, so drones can provide and maintain wireless emergency communication services during and after the disaster. Therefore, the SAR team can easily perform their tasks in a sequential manner. When a drone reaches the desired altitude, the affected area will be surveyed via a digital video camera. Then, collected images will be sent to a ground station for monitoring the area of operation and coordinating SAR teams with first responders' arrival. The authors of [40] introduced a multi-drone network architecture and demonstrated the network benefits in SAR and disaster assistance. Drones are all about the payload, so the type of event determines what equipment should be in the payload. Therefore, the most common drones used for public safety are the Da-Jiang Innovations (DJI) Inspire and DJI Phantom, as shown in Figure 3; both are from the DJI family. The DJI Phantom is easy to acquire, land and take off, flexible in terms of the camera tilting, and able to fly around objects, but even experienced pilots can get into tough spots. The features and advantages of the DJI drone are explained in [23]. Furthermore, DJI drones provide better SAR [55], so they can be used \begin{table}
\begin{tabular}{l l l l l l l l l} \hline \hline \multicolumn{1}{c}{**Ref.**} & \multicolumn{1}{c}{**Highlighted**} & \multicolumn{1}{c}{**SAR**} & \multicolumn{1}{c}{**IoT**} & \multicolumn{1}{c}{**Drone**} & \multicolumn{1}{c}{\begin{tabular}{c} **Smart** \\ **Cities** \\ \end{tabular} } & \multicolumn{1}{c}{\begin{tabular}{c} **Public** \\ **Safety** \\ \end{tabular} } & \multicolumn{1}{c}{\begin{tabular}{c} **Focus** \\ \end{tabular} } \\ \hline [PERSON] et al. [51] (2018) & \begin{tabular}{l} Drone as 0 th responders \\ and its best position \\ \end{tabular} & \(\surd\) & \(\surd\) & \(\surd\) & \(\surd\) & \(\surd\) & \begin{tabular}{c} 0 th responders are to arrive at \\ the disaster scenario before the \\ 1 st responder \\ \end{tabular} \\ \hline [PERSON] et al. [52] & \begin{tabular}{l} Signal strength between \\ drone and IoT device in \\ smart cities \\ \end{tabular} & \(\surd\) & \(\surd\) & \(\surd\) & \(\circ\) & \begin{tabular}{c} Predict the accurate \\ signal strength \\ \end{tabular} \\ \hline [PERSON] et al. [The proposed work] & \
\begin{tabular}{l} Collaboration of drone \\ and Internet of public \\ safety things \\ \end{tabular} & \(\surd\) & \(\surd\) & \(\surd\) & \(\surd\) & \(\circ\) &
\begin{tabular}{c} The collaboration of advanced \\ technologies for public safety \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cont._for all sorts of activities such as environmental monitoring, disaster management, mapping, and 3D modeling. During the launch of a DJI drone, it starts looking for interference, and when found it will try to localize the interferer. It will also change the flight plan to get the next meaningful measurement point, reducing the flight time. The DJI drones are efficient at capturing imagery of sufficient quality for the 3D mapping required for accident reconstruction and crime scene visualization in smart cities.