## 4 UAV Communication Network and Technology
### Communication Protocols in UAV Networks  
In recent years, a large number of research studies have focused on various aspects of UAV communication networks, leading to technological improvements and enhanced performance of UAV networks. Communication protocols can be used to transmit data between UAV devices based on Air-to-Air (A2A) and Air-to-Ground (A2G) methods (Figure 19) [64]. However, a major challenge for UAVs is the large operating area, often beyond the Line-of-Sight (LoS) range, so communication protocols in UAV networks need to ensure appropriate technological solutions, ensuring acceptable capacity and quality of service (QoS). To meet the above requirements, modern mobile technologies such as LTE, 5G, and 6G have been proposed for UAV networks due to their advantages in terms of broadband connectivity, low latency, and wide coverage. These technologies are suitable for UAVs operating over large areas and can support applications requiring large data transmission or continuous connectivity in mobile environments. Figure 20 shows the evolution roadmap from 1G to 6G, combining breakthrough technologies such as AI, virtualization, and high-speed communications. They create the foundation for a flexible, high-performance, and sustainable UAV network. Advanced technologies such as cell-less networks eliminate coverage limitations, while energy efficiency solutions optimize UAV operations. In addition, the development of technologies such as artificial intelligence (AI/ML), blockchain, VLC, and quantum computing will improve the operational efficiency of UAV networks with high-speed, secure, and stable transmission capabilities. In addition, WiFi is also a notable factor in building UAV communication networks. WiFi can play an important role in applications with a smaller operating range or in situations where temporary and cost-effective connectivity is required [65]. With the development of new WiFi standards such as WiFi 6 and WiFi 6E, many opportunities  
Figure 19: UAV networking: different aspects. are opening up for WiFi deployment in UAV networks (Figure 21). The following is a review of the most commonly used protocols in UAV networks, emphasizing the processing capabilities and dynamics of the network structure. Figure 21: Communication between UAVs supported by WiFi (IEEE 802.11). Figure 20: Evolution of mobile technology and communication solutions for UAV networks. * WiFi  
Most commercial UAVs use WiFi (IEEE 802.11) for communication as a low-cost, scalable solution. Although WiFi's throughput (theoretically ranging from 54 Mbps for 802.11a to 2.4 Gbps for 802.11 ax) is relatively lower than LTE and 5G, it is sufficient for most applications, including real-time high-resolution video streaming. In [65], an application solution was proposed to support forest fire suppression operations. Forest fires affect rural or suburban areas where the coverage of conventional networks (e.g., cellular networks) is weak or absent, or where fires are likely to occur. Therefore, UAVs can be used to establish a relay network between the command post managing the operations and firefighters, providing situational awareness to rescue forces. Firefighter mobility is a major challenge, as the UAV swarm must maintain both coverage and end-to-end connectivity to the Base Station (BS) of the command post. LoRaUAV, a UAV system based on LoRaWAN and Wireless Fidelity (WiFi), is designed to address these issues. In the LoRaUAV system, a WiFi mesh network of autonomous UAV LoRaWAN gateways is dynamically deployed to provide LoRaWAN coverage during firefighting operations. This network of flying LoRaWAN gateways receives data from the Ground Nodes (GNs) and forwards the data via WiFi to the control station. WiFi technology has a higher data rate. It allows aggregation of traffic originating from multiple GNs. The authors propose a two-layer network system called LoRaUAV based on an ad hoc WiFi network.