## 1 Introduction  
Recently, unmanned aerial vehicles (UAVs), generally known as drones, have been utilized in a variety of applications. UAVs are utilized nowadays for a variety of purposes, including data collection, public safety, transportation management, search and rescue, reconnaissance, and surveillance. UAV-assisted communication is a viable strategy for future 6G networks because of the shrinking of communication gear, as well as the flexible deployment and inexpensive cost of UAVs. UAVs are brand-new components of 6G networks and differ dramatically from traditional terrestrial communication nodes in many ways. It is important to highlight that 5G and 6G demand a level of network densification that has never before been necessary. This is extremely difficult and is a problem that aerial and ad hoc communications can directly solve. Through intelligent relaying and the use of broadband in remote locations and cut-off hubs, flying and ad hoc networks (FANETs) have the ability to usher in this technological revolution. To support local wireless networks, individual UAVs may function as aerial base stations [1]. There are a number of specific use cases and industries where UAVs have a variety of potential applications in wireless communication networks such as 5G and 6G. For example, in the logistics and transportation sector, UAVs can play an important role thanks to their fast and effective payload capacity. UAVs may be preferred in cases such as the rapid delivery of emergency medical supplies or the rapid shipment of critical parts. In the agricultural sector, UAVs can be an effective tool for phytosanitary monitoring, productivity improvement, and irrigation management. In the field of security and monitoring, UAVscan be used effectively in issues such as border security, fire monitoring, disaster management, and crime prevention. The media and entertainment industry are another area where UAVs can be used for creative shooting and impressive visual effects. Infrastructure monitoring and maintenance are also areas where UAVs are useful. UAVs can perform unmanned visual inspections of structures such as bridges, power lines, and buildings and detect abnormal conditions. Thanks to their ability to provide easy access to high points, UAVs can facilitate infrastructure-monitoring processes. With the development and improvement of advanced technologies, it is predicted that UAVs will be used more effectively in different industries. First, because of its large bandwidth, the THz band enables high data rates. To address the need for higher data rates, 6G networks may deliver substantially higher data rates by employing the THz spectrum. Second, within the frequency spectrum, the THz band allows for numerous parallel channels. This capability enables 6G networks to support a huge number of users. Third, because the THz band has minimal latency, it is a feasible option for ultra-low latency applications. THz communication enables real-time engagement by providing a quick and dependable connection. As a consequence of its features, such as fast data rates, large capacity, and low latency, THz band communication is being explored as a viable alternative for 6G networks. To meet rising bandwidth needs, the frequency band has steadily grown. Terahertz (THz)-band communications [2; 3] will be crucial for 6G [4; 5; 6] and beyond, even if the millimeter-wave (mmWave)-band [7; 8] is already influencing 5G. The final uncharted region of the frequency band is the THz band, which is located between optical bands and microwaves. In order to facilitate THz communications, technologies from both sides are being investigated. All actions beyond the 100 gigahertz (GHz) limit, below which, the majority of known mmWave use cases exist, are classified as THz by RF experts. Opticians, however, refer to any frequency below 10 THz as THz (the far infrared).