## 2 UAV Network Communication Model and Architecture
### Comment  
As analyzed above, we can see that the UAV swarm communication architecture technology has made great progress. When facing different mission scenarios, it is necessary to choose a suitable communication architecture. The advantages and disadvantages of the four presented architectural models are summarized in Table 2. From there, we can intuitively see that the centralized communication architecture is suitable for simple tasks. They require a small number of UAVs. Each UAV needs a long-range communication link with the central station. The decentralized communication architecture extends the communication range. The dedicated gateway UAV is responsible for UTI communication. The \"single-group ad hoc swarm network\" architecture is suitable for swarms with the same type of UAVs, while the \"multi-group ad hoc swarm network\" and \"multi-layer ad hoc swarm network\" architectures can be deployed using different types of UAVs. In the \"multi-group ad hoc swarm network\", communication between two different groups can also be delayed due to passing through many network ports. In terms of applicability and robustness, the \"multi-layer ad hoc swarm network\" architecture is a reliable system because it overcomes the SPOF.  
When discussing the advantages and disadvantages of UAV swarm communication architectures, we often focus on the requirements for high coverage and connection maintenance. Coverage plays an important role in information gathering and situation analysis. The real-time communication capability of UAV swarms can only be guaranteed if connections are maintained. However, UAV swarms often perform tasks in unknown environments. Threats and obstacles often appear randomly in time and space. Therefore, the ability to change the UAV formation configuration and the flexibility to join or leave the swarm are also necessary. For uninterrupted connection, the distance in the UAV swarm ad hoc network configuration must not exceed the sensitivity of the receiver. At the same time, the distance must be limited to the minimum signal-to-noise ratio (SNR) or the corresponding received signal strength indicator (RSSI) [35]. Here, the swarm models in nature are worth studying and applying, such as flocks of birds, flocks of fish, bees, fireflies, wolves, elephants, etc. However, the problem of ensuring connectivity and maintaining flexibility is facing great challenges in terms of security and information safety require  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Advantages and Disadvantages**} & \multirow{2}{*}{**Focused Communication**} & \multicolumn{3}{c}{**Decentralized**} \\ \cline{3-5}  & & **Single Group** & **Multi-Group** & **Multilayer** \\ \hline Integration of different types & No & Yes & Yes & Yes \\ of UAVs & No & Yes & No & Yes \\ \hline Self-configuring & No & Yes & Yes & Yes \\ \hline Forwarding information & No & Yes & Yes & Yes \\ \hline Computational resource & & & & \\ requirements for UAVs & Low & Medium & High & Very high \\ \hline Large media coverage? & No & Yes & Yes & Yes \\ \hline Low latency? & No & Yes & No & Yes \\ \hline \hline \end{tabular}
\end{table}
Table 2: Summary of the communication architecture.  
ments. Maintaining the balance between these two factors can become a future research direction and trend.