# Communication Infrastructure Design for Reliable UAV Operations in Air Mobility Corridors
### Research Gap, Contributions, and Paper Structure  
The rapid evolution of UAM necessitates the design of reliable communication infrastructures to ensure the safe, coordinated operation of UAVs in structured air corridors. While previous studies have addressed relay-based communication and aerial network planning, a major gap remains in the quantitative comparison of repeater deployment strategies under realistic reliability constraints. Existing works do not provide a unified modeling framework for evaluating communication availability based on redundancy configurations, coverage overlap, and corridor topology. Additionally, there is a lack of guidance for the strategic placement of radio repeater stations tailored to urban UAV corridor scenarios with varying reliability demands. This paper addresses the above gap by proposing a systematic framework for designing and evaluating communication strategies for UAV corridors. The main contributions are as follows:  
* Four deployment strategies (non-overlapping, fully overlapping, alternating redundant, and fully duplicated coverage) are defined and analyzed based on redundancy level, resource cost, and applicability. * The study introduces a set of continuous-time Markov chain models to quantify communication availability and unavailability under different deployment strategies, accounting for UAV traffic load and radio station failure/repair dynamics. * The paper compares strategies in terms of both infrastructure requirements and achieved reliability, demonstrating exponential gains in availability with increasing redundancy and identifying optimal strategies for different operational scenarios. * The proposed framework is applied to a case study in the Greenline district of Astana, Kazakhstan, demonstrating how strategy selection and repeater placement can be adapted to real corridor geometry and urban communication challenges. * A step-by-step methodology is presented for planning repeater-based UAV corridor networks, supporting segmented deployment, non-linear path layouts, and strategy optimization. While some forms of communication redundancy, such as overlapping coverage and relay-based transmission, have been discussed in prior works on UAV networking and ground communication infrastructure, the four deployment strategies presented in this paper are, to the best of the authors' knowledge, the first to be formalized and comparatively analyzed within a unified Markov modeling framework specific to structured air mobility corridors. These strategies--ranging from non-overlapping coverage to full duplication--represent an adaptation and extension of existing redundancy concepts, tailored specifically to the operational and geometric constraints of urban UAV corridors. Strategy 1 reflects the minimal baseline seen in legacy point-to-point radio systems, while Strategy 2 aligns with standard dual-coverage designs used in high-reliability applications. Strategy 3 introduces a novel alternating redundancy configuration that balances resource use and fault tolerance and is not found in prior literature in this form. Strategy 4 builds on principles from critical system engineering, combining full overlap and physical duplication, akin to fail-operational designs in aviation-grade systems. By articulating these configurations as discrete, comparable strategies, this work provides a structured design space and evaluation methodology for planners and system integrators working on UAM communication infrastructure. The remainder of this paper is organized as follows. Section 2 describes the proposed communication strategies and the Markov modeling approach for analyzing communication availability. Section 3 presents the quantitative results comparing the deployment strategies, including resource requirements, reliability performance, and a detailed case study implementation in Astana. Section 4 discusses practical implications, system design guidelines, adaptation to complex corridor layouts, and future research directions.