# Coverage Area Decision Model by Using Unmanned Aerial Vehicles Base Stations for Ad Hoc Networks
## 1 Introduction  
One of the fundamental requirements of any new and advanced network, especially digital agriculture networks where full-service coverage needed. Precision agriculture optimizes the agricultural processes to certify final production. The users in these networks are always looking for full coverage and strong signal networks and services. In digital agriculture networks, the services and coverage should be available anytime and anywhere. The choice of users is always based on these basic criteria, especially in cellular networks. With new and integrated technologies, user demand has increased to the point where they need faster, more reliable, and more secure data communication [1, 2]. This user expectation is fourfold, especially in complex areas based on network systems, such as in a disaster-affected area where the connectivity and permanent infrastructure such as Base Station (BS) deployment is not possible or is difficult. On the other hand, some examples are those where the services and BS are available, but the user density is high. Still, various strategies have been adopted and designed to address these issues and meet user expectations [3, 4]. For long-range data communications, high-power transmitters have been adopted, but such communication systems require energy resources. In cellular networks, the land areas are distributed into smaller areas called cells. These cellular network cells are joined together to increase the geographical area. Normally, each of these cells is served by a fixed location tower known as a Base Transceiver Station (BTS) or Base Station (BS) [5]. In these networks, the devices are connected with cellular towers (PECO cells/microcells), and smaller cells are connected with large cells, which are further connected with core networks [6]. The smaller cells are further connected directly to the core networks to acquire basic services for users. The cell size is different and considered by using the user's density in the networks. These cells can be deployed in macro, micro, or pico levels [7; 8]. A macrocell usually covers a wide area of radius, which is around 25 km depending upon the density of users. The micro cells normally have a coverage area of up to 2 km, whereas the pico cells are used to cover the smaller areas such as offices, shopping malls, and buildings [9]. The need for a smaller cell size is not only dependent on the coverage area but also affects user capacity. By dividing the cell into smaller levels, the reusability of the channel increases by many folds. The fixed BS provides best-effort connectivity services. However, the BS works in ideal situations such as proper tower foundation space, feasible installation, and obstacle-free areas. While they have many advantages, BS services also suffer from higher setup costs, maintenance issues, and other cumbersome processes. Moreover, where the deployment of physical infrastructure is difficult or there are more chances of natural disasters, such as floods and earthquakes [10], quick restoration and recovery of uninterrupted connectivity services are not possible. Some other issues also exist, such as power supply issues to the BS, generator cost, land issues, coverage, capacity, and road coverage concerns. To address these issues, Unmanned Aerial Vehicles (UAVs) based on microcellular solutions have been used to offer temporary ground-based solutions [11; 12; 13]. Such solutions are also being explored for increasing the coverage in fifth-generation (SG) networks. These aerial BSs are deployed using drones, such as Drone Base Stations (DBSs), and continuously adapt their moving directions to provide higher Quality of Service (QoS) for mobile users on the ground [14; 15]. The role of UAVs with all new and fast data communication services is to provide broadcasting and point-to-point communication. These new technologies overcome the existing issues in typical cellular networks.