# Artificial Intelligence-Based Autonomous UAV Networks: A Survey
## 4 Security, Safety, and Privacy Management
### Physical Layer Security and Safety  
At a broader level, we may define physical layer security as techniques to secure our communication over the channel against various attacks, including eavesdropping or jamming. Two typical UAV communication scenarios are illustrated in Figure 5.  
Figure 4: Security, safety, and privacy classification of UAV networks. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Scope** & **Autonomous** & **Computational** & **Channel** & **Interference** & **Security and** & **Reference** \\  & **Features** & **Intelligence** & **Modeling** & **Management** & **Safety** & **Reference** \\ \hline mm wave UAV & \multirow{2}{*}{Beam forming} & \multirow{2}{*}{\(\surd\)} & Quasi-static, & \multirow{2}{*}{\(\surd\)} & \multirow{2}{*}{-} & [68] \\ cellular network & & & & Rayleigh fading & & & \\ \hline Channel access & \multirow{4}{*}{\(\surd\)} & \multirow{4}{*}{\(\surd\)} & Free-space path & \multirow{4}{*}{\(\surd\)} & \multirow{4}{*}{-} & [70] \\ with & & & & loss with LOS & & & \\ \cline{1-1} array (TDM) & & & & & & \\ \hline Trajectory & \multirow{4}{*}{\(\surd\)} & \multirow{4}{*}{\(\surd\)} & Additive white & \multirow{4}{*}{\(\surd\)} & \multirow{4}{*}{-} & [74] \\ optimization & & power control & & (AWGN) & & & \\ \hline MAC protocol & Power optimization & \(\surd\) & Rician fading & \(\surd\) & - & [75] \\ \hline MAC protocol & \multirow{4}{*}{\(\begin{array}{c}\text{Throughput}\\ \text{optimization}\end{array}\)} & \multirow{4}{*}{\(\surd\)} & Free-space path & \multirow{4}{*}{-} & \multirow{4}{*}{-} & [76] \\  & & & loss with LOS & & & \\ \hline MAC protocol & Power optimization & \(\surd\) & Free-space path & \multirow{4}{*}{\(\surd\)} & \multirow{4}{*}{-} & [77] \\  & & & loss with LOS & & & \\ \hline MAC protocol & \multirow{4}{*}{\(\begin{array}{c}\text{Trajectory planning,}\\ \text{resource}\\ \text{management}\end{array}\)} & \multirow{4}{*}{\(\begin{array}{c}\text{LOS and}\\ \text{Non-LOS}\\ \text{(NLOS)}\end{array}\)} & \multirow{4}{*}{\(\surd\)} & \multirow{4}{*}{-} & [78] \\  & & & & & \\ \hline MAC protocol & Power optimization & \(\surd\) & LOS, NLOS & \(\surd\) & - & [79] \\ \hline MAC protocol & \multirow{4}{*}{\(\begin{array}{c}\text{Power and placement}\\ \text{optimization}\end{array}\)} & \multirow{4}{*}{\(\surd\)} & Additive white & \multirow{4}{*}{\(\surd\)} & \multirow{4}{*}{-} & [80] \\  & & & (AWGN) & & & \\ \hline Rate-splitting & \multirow{4}{*}{Beam forming} & \multirow{4}{*}{\(\surd\)} & Additive white & \multirow{4}{*}{\(\surd\)} & \multirow{4}{*}{-} & [82] \\  & & & (AWGN) & & & \\ \hline Rate-splitting & \multirow{4}{*}{Spectral efficiency} & \multirow{4}{*}{\(\surd\)} & Additive white & \multirow{4}{*}{\(\surd\)} & \multirow{4}{*}{-} & [86] \\  & & & (AWGN) & & & \\ \hline \end{tabular}
\end{table} 
Table 3: _Cont._Scenario (a) in Figure 5a illustrates the situation when the UAV is trying to communicate with the Earth station. In this case, it is much easier for any illegitimate user to eavesdrop on ongoing communication. However, if the Earth station tends to communicate with UAV, eavesdropping is not that simple. Scenario (b) (Figure 5b) has a natural advantage over Scenario (a). One of the solutions to the above-stated problem is identified as tracking or localizing the potential eavesdropper. Many research studies [100; 101; 102] have focused on this and proposed solutions, including mounting cameras or radars to identify or track any potential attacker. Introducing an anti-jamming signal or noise is another solution proposed by researchers [51; 103]. The two scenarios illustrated in Figure 5 are commonly classified as passive eavesdropping attacks. However, active eavesdropping is more harmful to the network compared to passive eavesdropping. In active eavesdropping, the attacker tends to attack and play with the main channel of communication. Various solutions are proposed to avoid active eavesdropping attacks as well. One of the popular solutions is by using joint-trajectory and resource allocation for the UAVs [52; 53; 54].