Urban Air Mobility

Description

Urban Air Mobility (UAM) is a service concept describing the safe and efficient operation of manned and unmanned aerial vehicles in and around urban areas, typically at low altitudes. It encompasses passenger transport using electric vertical take-off and landing (eVTOL) aircraft, cargo delivery by drones, emergency services, and aerial inspection. In the 3GPP context, UAM is addressed primarily as a connectivity challenge: aerial vehicles require reliable command-and-control links, payload data connectivity, and in some cases voice or video services, all while moving through three-dimensional airspace that cellular networks were not originally designed to cover optimally. Specifications 22.870 and 33.759 provide the service requirements and security framework for supporting UAM over 3GPP systems.

Architecturally, supporting UAM involves both the terrestrial network and the aerial domain. On the network side, cells must provide coverage at altitudes beyond traditional ground-level planning, which affects antenna tilting, interference management, and handover behavior. Aerial user equipment (UE) may connect directly to terrestrial base stations or, in some deployments, via satellite or high-altitude platform stations that integrate with the 5G core. The core network must support mobility management for fast-moving aerial UEs, quality-of-service differentiation between command-and-control and payload traffic, and network slicing to isolate UAM traffic from other services. Security is especially critical: 33.759 defines the security requirements for UAM, including authentication of aerial vehicles, protection of command-and-control links, and privacy considerations.

How UAM works in a 3GPP system begins with the aerial UE establishing a connection like any other UE, but with additional considerations. The UE may benefit from enhanced mobility features such as flight path information reporting, which allows the network to anticipate handovers and reduce interruption. Command-and-control links must meet stringent latency and reliability targets because loss of control connectivity can have safety implications. The network may use network slicing to create a dedicated UAM slice with appropriate coverage, latency, and reliability characteristics. Edge computing can host traffic management and collision avoidance functions close to the airspace, reducing latency for time-critical operations.

Key components of UAM in 3GPP include the aerial UE, the radio access network adapted for aerial coverage, the 5G core with slicing and policy functions, and the external UAM service ecosystem including traffic management authorities and operators. The specifications 22.870 and 33.759 define respectively the service requirements and the security architecture and procedures that support these components. Interworking with aviation authorities and unmanned traffic management systems is also part of the broader picture, though not fully within 3GPP's scope.

For engineers and students, UAM is an important case study in how 3GPP extends its framework to new verticals. It illustrates the interaction between radio coverage, mobility, QoS, security, and regulation. As UAM moves from trials to commercial deployment, the 3GPP features defined in Rel-19 and Rel-20 will form the connectivity foundation, and understanding them is essential for anyone working on aerial communications, smart city infrastructure, or advanced mobility services.

Purpose & Motivation

Urban Air Mobility exists to address the growing demand for air transportation and aerial services within densely populated areas, where ground infrastructure is congested and geographic constraints limit expansion. Traditional aviation operates between airports and at higher altitudes, leaving a gap for short-range, intra-city, and low-altitude operations. UAM fills this gap with eVTOL aircraft and drones, promising faster passenger journeys, efficient package delivery, and new emergency response capabilities. For these operations to be safe and scalable, they require dependable communication links, which is where 3GPP and its cellular technologies become essential.

Before UAM was formally addressed in 3GPP, cellular networks were optimized for terrestrial users. Aerial vehicles using cellular connectivity faced issues such as fragmented coverage at altitude, interference from many cells being visible simultaneously, and mobility procedures not tuned for three-dimensional movement. Security frameworks also did not specifically account for remotely piloted or autonomous aircraft. The introduction of UAM requirements in Rel-19 and the security work in Rel-20 address these limitations by defining service expectations and protection mechanisms tailored to aerial operations.

The motivation for UAM in 3GPP is therefore twofold: to enable a new market for cellular connectivity, and to ensure that when aerial vehicles do use cellular networks, they do so safely, securely, and without degrading service for ground users. By specifying requirements in 22.870 and security in 33.759, 3GPP provides a foundation that regulators, operators, and manufacturers can build upon, harmonizing connectivity expectations across the emerging UAM ecosystem.