Uncrewed Aerial Vehicle – Controller

Description

The Uncrewed Aerial Vehicle – Controller (UAV-C) is a standardized service architecture defined by 3GPP to facilitate the command and control of UAVs, commonly known as drones, using 3GPP cellular networks as the communication link. The architecture involves several key network functions and interfaces to ensure secure, reliable, and low-latency connectivity between the UAV Controller (the ground-based pilot or automated system) and the UAV itself. The UAV-C service is typically accessed via a UAV Service Supplier (USS) or UAS Traffic Management (UTM) system, which interfaces with the 3GPP network to authenticate the controller, authorize the UAV flight, and establish the necessary communication paths.

At its core, the UAV-C functionality leverages existing 3GPP core network capabilities, such as the Policy Control Function (PCF), Unified Data Management (UDM), and Session Management Function (SMF), but extends them with service-specific enhancements. For instance, the Network Exposure Function (NEF) may be used to securely expose network capabilities to the USS/UTM for service authorization and flight path validation. The communication itself can utilize either a direct C2 link between the controller and the UAV or an indirect link via the USS, depending on the operational scenario and regulatory requirements. The system supports both unicast and multicast delivery for efficient command dissemination in fleet operations.

The service ensures that the C2 link meets stringent requirements for availability, integrity, and low latency, which are critical for safe UAV operation, especially in BVLOS scenarios. This is achieved through network slicing, QoS enforcement, and continuous connectivity management, including handovers between cells as the UAV moves. The architecture also incorporates security mechanisms to prevent unauthorized access and protect the C2 communication from interception or manipulation, aligning with aviation safety standards.

Purpose & Motivation

The UAV-C service was created to address the growing need for reliable, beyond-visual-line-of-sight (BVLOS) command and control of drones using ubiquitous cellular networks. Prior to its standardization, drone operations were largely limited to short-range, direct radio links (e.g., Wi-Fi or proprietary RF), restricting operational range and complicating integration into controlled airspace. The lack of a standardized cellular-based C2 solution hindered scalable commercial drone applications like delivery, infrastructure inspection, and aerial photography.

3GPP initiated work on UAV support in Release 15, focusing initially on identification and connectivity. Release 17 specifically introduced the UAV-C service to provide a holistic framework for authorized C2 communications, enabling drones to operate safely over wide areas. This standardization solves key problems: it provides a secure, licensed-spectrum alternative to unlicensed bands, reduces the need for custom ground infrastructure, and facilitates regulatory compliance by offering traceable, authenticated links. It allows seamless mobility across cellular coverage areas, which is essential for long-distance drone missions.

The motivation stems from the aviation industry's push towards UAS Traffic Management (UTM) and the integration of drones into national airspace systems. By leveraging existing 4G/5G networks, UAV-C lowers deployment costs and accelerates time-to-market for drone service providers. It addresses limitations of previous ad-hoc solutions, which lacked interoperability, scalability, and the robust QoS and security features required for critical C2 links in shared airspace.