# Communication Infrastructure Design for Reliable UAV Operations in Air Mobility Corridors
### Related Works  
In designing advanced drone systems, maintaining the connection between the aircraft and the control center represents a fundamental challenge. Standard affordable wireless components suffer from limited range and vulnerability to physical obstructions. Implementing relay networks offers an effective solution to these limitations, significantly enhancing drone communication capabilities during beyond-line-of-sight operations and when navigating environments with obstacles blocking direct transmission paths. The study [8] develops and tests a communication relay system for beyond-line-of-sight operations involving UAVs, specifically using one quadrotor to relay radio communications to another. The process involved constructing UAVs as airborne platforms, selecting and assembling hardware for the relay system, and developing software for mission control and communication. The paper [9] focuses on optimizing the placement of relay UAVs to maximize end-to-end packet delivery ratio in multi-hop networks. It discusses dynamic relay positioningand proposes a distributed method for optimal placement, improving data throughput by up to 15%  
The article [10] reviews the evolution of UAM expected to address the challenges of traditional ground-based transportation such as congestion and high infrastructure costs. It highlights the impact of drones and the collaboration between aviation and automotive industries to develop UAM, which promises to be an environmentally friendly, cost-effective, and faster alternative. Cellular networks, owing to their widespread base station infrastructure, have emerged as strong candidates for delivering these connectivity solutions to UAVs operating in airspace [11]. However, traditional cellular networks are inherently optimized for terrestrial users. Specifically, base station antennas are generally down-tilted to provide optimal coverage at ground level, resulting in inconsistent and often inadequate coverage at higher altitudes where aerial vehicles operate [12; 13]. In addition to coverage issues, UAVs can introduce substantial uplink interference due to their line-of-sight visibility to multiple base stations simultaneously operating on the same frequencies. This phenomenon can disrupt cellular services for users on the ground [14; 15]. Hence, while cellular networks hold the potential for supporting UAM, their use demands specialized optimization strategies to ensure reliable aerial coverage while preserving the integrity of ground-level services. Ultra-reliable urban air mobility networks are described in the study [16]. It proposes solutions like optimal antenna tilting, frequency reuse with narrow beams, and assistive transmission from a master UAM to improve link reliability to 99.9%  
A novel probability model for urban air mobility is discussed in [17]. This study introduces a line-of-sight probability model that accounts for urban topography and dynamic ground vehicle positioning to improve interference prediction and ensure reliable communication in high-density aerial traffic. The conventional terrestrial networks for communication support in UAM, reliant on fixed base stations, are limited in their ability to offer continuous coverage. Additionally, remote or underdeveloped regions, such as mountainous terrains or oceanic expanses, often lack the necessary infrastructure for reliable network access [18]. To overcome these limitations and realize the expansive vision of sixth-generation (6G) mobile communication technology, researchers are turning their focus to a next-generation architecture known as space-air-ground integrated networks (SAGINs). SAGINs integrate terrestrial networks (TNs) with non-terrestrial networks (NTNs), combining satellites, aerial platforms (such as UAVs or high-altitude platforms), and ground-based infrastructure into a unified, layered network with high mobility and broad spatial reach [19]. In recent years, SAGINs have emerged as a prominent research direction in the mobile communication landscape.