## 3 UAV 6G Networks
### 6G Application Requirements
#### 3.2.1 High-Precision Positioning and Seamless Coverage  
Unmanned aerial vehicles performing operations while airborne at various level of air space necessitate accurate positioning, precise navigation and excellent network coverage and the same aspects are vital for the network's growing infrastructure, expansion and convergence as shown in Figure 9. While the UAVs are flying independently, a secure connection and vast network coverage ensures uninterrupted connectivity. Covering a wide range of coverage at varied elevations while maintaining seamless connectivity is a critical problem for 4G/5G cellular networks. Positioning based on high precision is expected to be provided by 6G while employing radar technology. Moreover, utilization of modern concepts such as 3D placement permits the accurate locating of unmanned aerial vehicles and moving devices in the sky [68]. Upcoming, 6G communication networks may enhance the quantity of connected unmanned aerial vehicles in densely populated scenarios by 107 devices/km\({}^{2}\) which is 10 times greater than its predecessor, wireless communication model density. Beyond the vision line of sight, improved quality, robust, reliable and secure networks with vast speedy coverage, the 6G network is expected to provide connectivity that is efficient, cost effective and speedy, promising the future needs of the world [69]. The high-speed OWC system's high-capacity backhaul network enables a significant volume of UAV traffic data.  
In the study [70], 6G multilayer architecture comprising of terrestrial layer, airborne layer and space layer is discussed. [PERSON] et al. describe satellite communications asnow undergoing significant advancements and 6G technology is being integrated into satellite networks. This is paving the way for a significant global turning point in the satellite-enabled service industry. 6G communication model integrated with satellites will provide enveloping services worldwide to support both dense and less-dense areas. In order to materialize the same, 6G systems are required to amalgamate terrestrial, airborne assets including drones/ UAVs and satellite infrastructure in different orbits. 6G technologies are to offer dependable, guaranteed bandwidth connections to users on ships in the sea, in the air, trains and in cars covering entire globe. Satellites assist operations with the provision of the desired bandwidth connection. Without existence of significant terrestrial infrastructure, satellites would be able to provide connections that are considered reliable in a sustainable manner.  
In the study [71], space-air-ground (SAG) integrated network is discussed in detail. It states that UAV systems can be employed as a service to supplement the idea of 6G-SAG in future. Moreover, blockchain technology is a vital requirement for 6G-SAG, in order to store network activity logs in an immutable, decentralized manner. Through employment of cryptographic hash drones, ground stations and satellites can serve as the block storage media.  
In the study [72], it is envisaged that 6G network would ensure the provision of numerous services and unblemished network coverage for everyone and everything. The integrated satellite-terrestrial network architecture promises to provide worldwide broadband connectivity by combining advantages of both types of networks, to a wide range of users around the globe. The stated perceived communication model has already received attention from both academia and business.