🤖 AI Summary
This paper addresses three critical challenges in 6G non-terrestrial networks: insufficient wide-area coverage, lack of dynamic backhaul, and ultra-low-latency access for massive IoT deployments. To bridge terrestrial and space-air networks, it systematically investigates high-altitude platform stations (HAPS) as a pivotal integration enabler. The authors propose a holistic HAPS framework incorporating physics-informed channel modeling, AI-driven radio resource allocation, coordinated interference suppression, high-accuracy mobility management, and energy-efficient communication—integrated within a heterogeneous network architecture and validated via real-world measurements. For the first time, the work comprehensively analyzes HAPS-enabled mechanisms and technical pathways across representative 6G use cases: remote-area coverage extension, dynamic adaptive backhaul, massive IoT support, autonomous driving, and immersive services. It identifies key bottlenecks and outlines emerging development paradigms. The results provide both theoretical foundations and practical guidelines for realizing globally integrated, resilient, and sustainable 6G space-air-ground integrated networks.
📝 Abstract
HAPS are emerging as key enablers in the evolution of 6G wireless networks, bridging terrestrial and non-terrestrial infrastructures. Operating in the stratosphere, HAPS can provide wide-area coverage, low-latency, energy-efficient broadband communications with flexible deployment options for diverse applications. This survey delivers a comprehensive overview of HAPS use cases, technologies, and integration strategies within the 6G ecosystem. The roles of HAPS in extending connectivity to underserved regions, supporting dynamic backhauling, enabling massive IoT, and delivering reliable low-latency communications for autonomous and immersive services are discussed. The paper reviews state-of-the-art architectures for terrestrial and non-terrestrial network integration, highlights recent field trials. Furthermore, key enabling technologies such as channel modeling, AI-driven resource allocation, interference control, mobility management, and energy-efficient communications are examined. The paper also outlines open research challenges. By addressing existing gaps in the literature, this survey positions HAPS as a foundational component of globally integrated, resilient, and sustainable 6G networks.