High-Altitude Platforms in the Low-Altitude Economy: Bridging Communication, Computing, and Regulation

TL;DR

This article proposes a five-stage evolutionary roadmap for HAPs in the LAE: from serving as aerial infrastructure bases, to becoming super back-ends for UAV, to acting as frontline support for ground users, further enabling swarm-scale UAV coordination, and ultimately advancing toward edge-air-cloud closed-loop autonomy.

Abstract

The Low-Altitude Economy (LAE) is rapidly emerging as a new technological and industrial frontier, with unmanned aerial vehicles (UAVs), electric vertical takeoff and landing (eVTOL) aircraft, and aerial swarms increasingly deployed in logistics, infrastructure inspection, security, and emergency response. However, the large-scale development of the LAE demands a reliable aerial foundation that ensures not only real-time connectivity and computational support, but also navigation integrity and safe airspace management for safety-critical operations. High-Altitude Platforms (HAPs), positioned at around 20 km, provide a unique balance between wide-area coverage and low-latency responsiveness. Compared with low earth orbit (LEO) satellites, HAPs are closer to end users and thus capable of delivering millisecond-level connectivity, fine-grained regulatory oversight, and powerful onboard computing and caching resources. Beyond connectivity and computation, HAPs-assisted sensing and regulation further enable navigation integrity and airspace trust, which are essential for safety-critical UAV and eVTOL operations in the LAE. This article proposes a five-stage evolutionary roadmap for HAPs in the LAE: from serving as aerial infrastructure bases, to becoming super back-ends for UAV, to acting as frontline support for ground users, further enabling swarm-scale UAV coordination, and ultimately advancing toward edge-air-cloud closed-loop autonomy. In parallel, HAPs complement LEO satellites and cloud infrastructures to form a global-regional-local three-tier architecture. Looking forward, HAPs are expected to evolve from simple platforms into intelligent hubs, emerging as pivotal nodes for air traffic management, intelligent logistics, and emergency response. By doing so, they will accelerate the transition of the LAE toward large-scale deployment, autonomy, and sustainable growth.

Figures (6)

• Figure 1: Overview of LAE applications and supporting networks. The applications of the LAE can be categorized into three core domains: communication, sensing, and services. Communication focuses on addressing issues such as insufficient coverage, excessive latency, and discontinuous connectivity with providing information support. Sensing targets environmental monitoring and situational awareness, with an emphasis on data acquisition. Services highlight scheduling, regulation, and coordination, underscoring system-level integration and efficient operation. To enable these applications, a comprehensive air–space–ground network is leveraged, whose advantages and limitations are summarized.
• Figure 2: HAPs as aerial super nodes in the LAE, enabling four key dimensions: Communication, Sensing $\&$ Regulation, Computation, and Cooperative Intelligence.
• Figure 3: Comparison of communication characteristics across different infrastructures for eVTOL connectivity. (a) One-way propagation delay versus horizontal separation distance, (b) Corresponding SNR and achievable capacity.
• Figure 4: Representative simulation results showing (a) the system model of a cooperative HAPs–UAV bistatic ISARAC scenario, (b) the optimized UAV trajectory that enhances synthetic aperture diversity while maintaining a reliable downlink for ISAC illumination from the HAPs, and (c) the ISAC performance trend illustrating balanced throughput and sensing robustness under shared energy constraints.
• Figure 5: Impact of HAPs-enabled computation offloading on UAV task executability. (a) Without HAPs. (b) With HAPs offloading support .