Enhancing connectivity for emergency vehicles through UAV trajectory and resource allocation optimization

Effective communication for emergency vehicles – such as ambulances and fire trucks – is essential to support their operations in various traffic and environmental conditions. In this context, this paper investigates a vehicular communication system assisted by an Unmanned Aerial Vehicle (UAV), which adjusts its trajectory and resource allocation according to communication needs. The system classifies vehicles into two groups to address their varying service requirements: emergency vehicles, which require a minimum instantaneous data rate to access critical information timely, and normal vehicles. To support both categories effectively, this paper proposes a joint optimization approach that coordinates UAV trajectory planning and Dynamic Bandwidth Allocation (DBA). The objective is to maximize the minimum average data rate for normal vehicles while ensuring that emergency vehicles maintain an instantaneous rate above a predefined threshold. This approach takes into account some system constraints, including UAV propulsion power consumption, mobility limitations, and backhaul capacity. To tackle the resulting non-convex problem, an iterative optimization method is employed, where the original problem is decomposed into two subproblems: bandwidth allocation and UAV trajectory design. In each iteration, the trajectory subproblem is solved using the Successive Convex Approximation (SCA) method. Numerical results confirm that the proposed solution achieves superior performance in meeting service requirements compared to baseline methods.