Ground Based Detect and Avoid for an Area

Description

Ground Based Detect and Avoid for an Area (GBDAAA) is a Rel-19 feature specified in 3GPP TS 24.577 and TS 24.578 that defines how ground-based detection systems can support detect-and-avoid (DAA) capabilities for aerial user equipment (UE) connected to 5G networks. Unlike airborne DAA, which relies on sensors and processing onboard the aircraft, GBDAAA uses terrestrial infrastructure—such as radar, cameras, RF sensors, or other ground-based surveillance systems—to monitor a defined geographic area for non-cooperative intruders (e.g., other drones, birds, or aircraft not broadcasting their position). The detection results are then conveyed to the aerial UE or to a UAV controller through the cellular network, enabling timely avoidance maneuvers.

Architecturally, GBDAAA leverages the 5G system's service-based architecture and the UAV-specific enhancements introduced in earlier releases. The ground-based detection function may be hosted at the edge or in the cloud and is exposed to the network via application programming interfaces (APIs). The 3GPP core network, particularly the Network Exposure Function (NEF) and the Unified Data Management (UDM), plays a role in authorizing and configuring the service for specific UAVs. The aerial UE or its controller subscribes to the GBDAAA service, and the network delivers detection alerts and avoidance commands using existing communication protocols, such as the UAV-to-UTRAN (Uu) interface or PC5 sidelink for direct communication.

The operation of GBDAAA involves several key components: a detection sensor network, a detection fusion and tracking system, a service enabler, and the 5G network itself. The sensor network continuously scans the designated area and reports tracks of intruders. The fusion system correlates and filters these reports to produce reliable intruder tracks. The service enabler formats the tracks into standardized messages (e.g., using the ASTM Remote ID or a 3GPP-specific format) and sends them to subscribed UAVs. The 5G network ensures low-latency, reliable delivery, potentially using network slicing to guarantee quality of service for safety-critical DAA messages.

GBDAAA is particularly important for beyond-visual-line-of-sight (BVLOS) operations, where the remote pilot cannot see the airspace around the drone. By providing ground-based detection, it complements onboard DAA sensors and can cover areas where airborne sensors may be limited by size, weight, and power constraints. It also enables a cooperative traffic management ecosystem where ground infrastructure assists in deconflicting airspace, especially in urban environments or near airports.

The feature is part of the broader 3GPP effort to support Unmanned Aircraft Systems (UAS) and Urban Air Mobility (UAM). It builds on earlier work such as the UAV identification and tracking enablers (Rel-17) and the enhanced DAA support (Rel-18). GBDAAA in Rel-19 focuses on standardizing the interfaces and procedures for ground-based detection services, ensuring interoperability between different vendors and service providers. This standardization is crucial for scaling UAS operations and integrating them safely into the national airspace.

Purpose & Motivation

GBDAAA exists to address the safety and regulatory requirement for detect-and-avoid (DAA) in unmanned aviation, particularly for beyond-visual-line-of-sight (BVLOS) operations. Regulatory bodies such as the FAA and EASA mandate that drones must be able to detect and avoid other aircraft. While airborne DAA systems are being developed, they face limitations in size, weight, power, and cost, especially for small drones. Ground-based detection offers a complementary or alternative solution, particularly in areas with high traffic density or where airborne sensors are less effective.

Before GBDAAA, ground-based detection systems were proprietary and not integrated with cellular networks. There was no standardized way for a drone to receive detection information from ground infrastructure via 5G. This lack of standardization hindered interoperability and scalability. GBDAAA fills this gap by defining how ground-based detection data is delivered to UAVs over 3GPP networks, enabling a unified approach that can be adopted by multiple vendors and operators.

The feature also supports the vision of U-space and UTM (Unmanned Traffic Management), where multiple stakeholders—drone operators, air navigation service providers, and cellular operators—collaborate to ensure safe airspace integration. By standardizing the interface, GBDAAA allows cellular operators to offer DAA as a service, potentially creating new revenue streams and accelerating the adoption of commercial drone operations.