Survey on Aerial Radio Access Networks: Toward a Comprehensive 6G Access Infrastructure (2102.07087v2)

Abstract: Current network access infrastructures are characterized by heterogeneity, low latency, high throughput, and high computational capability, enabling massive concurrent connections and various services. Unfortunately, this design does not pay significant attention to mobile services in underserved areas. In this context, the use of aerial radio access networks (ARANs) is a promising strategy to complement existing terrestrial communication systems. Involving airborne components such as unmanned aerial vehicles, drones, and satellites, ARANs can quickly establish a flexible access infrastructure on demand. ARANs are expected to support the development of seamless mobile communication systems toward a comprehensive sixth-generation (6G) global access infrastructure. This paper provides an overview of recent studies regarding ARANs in the literature. First, we investigate related work to identify areas for further exploration in terms of recent knowledge advancements and analyses. Second, we define the scope and methodology of this study. Then, we describe ARAN architecture and its fundamental features for the development of 6G networks. In particular, we analyze the system model from several perspectives, including transmission propagation, energy consumption, communication latency, and network mobility. Furthermore, we introduce technologies that enable the success of ARAN implementations in terms of energy replenishment, operational management, and data delivery. Subsequently, we discuss application scenarios envisioned for these technologies. Finally, we highlight ongoing research efforts and trends toward 6G ARANs.

Overview of Aerial Radio Access Networks Toward 6G

The paper "Survey on Aerial Radio Access Networks: Toward a Comprehensive 6G Access Infrastructure" presents a comprehensive exploration of aerial radio access networks (ARANs) envisioned to integrate seamlessly into sixth-generation (6G) communication systems. ARANs represent an innovative strategy to augment existing terrestrial network infrastructures by incorporating airborne components such as unmanned aerial vehicles (UAVs), drones, and satellites. This paper meticulously covers recent advances in ARAN-related studies, proposing it as a promising solution for bridging communication gaps in underserved areas.

Key Contributions

1. Comprehensive Survey of ARANs: The paper meticulously reviews existing literature on ARANs, identifying gaps and future research directions in relation to 6G technologies. This involves a thorough investigation of ARAN architectures, fundamental features, and enabling technologies critical for developing 6G networks.
2. System Modeling and Architecture: The authors dissect ARAN systems from varying perspectives, including transmission propagation, energy consumption, and network mobility. They provide an extensive discussion on the architecture of multitier ARAN systems, illustrating how these can effectively support 6G networks by aligning with existing terrestrial systems.
3. Technological Integration: A significant portion of the paper focuses on integrating ARANs with existing network management and operational technologies such as network softwarization, mobile cloudization, and data mining techniques. These integrations are crucial for ARANs to function effectively within 6G infrastructures.
4. Energy Replenishment Technologies: Considering the operational limitations due to energy storage, various energy replenishment techniques such as wireless charging and energy harvesting are outlined as vital components for sustainable ARAN operations.
5. Application Scenarios: The paper discusses potential scenarios where ARANs could be deployed, including event-based, scheduled, and permanent communications. These include disaster management, SAR operations, aerial surveillance, and providing network services in sparsely populated areas.

Empirical Findings and Implications

The paper reports strong empirical findings emphasizing the feasibility and effectiveness of ARAN systems in global network infrastructures. Key numerical results indicate that ARANs have a high line-of-sight communication probability due to their airborne nature, enabling efficient and reliable connectivity strategies for remote areas. Moreover, the hierarchical networking among LAP, HAP, and LEO tiers proposes a robust model to support ubiquitous communication needs.

The implications of this research are substantial both theoretically and practically. ARANs practically aid in overcoming barriers faced by terrestrial systems, offering flexible, reliable, and scalable networking solutions. Theoretically, ARANs challenge existing network paradigms, pushing boundaries in multi-access and high-frequency spectrum utilization within 6G.

Future Directions and Challenges

Looking forward, the paper identifies several challenges and future research directions. Among these include the requirement for intelligent radio systems configured to exploit AI technologies for network optimizations, overcoming high spectrum exploitation challenges, ensuring network stability amid high mobility, and tackling security and privacy concerns. Moreover, the pressing need for refined simulation tools to assess ARAN behaviors accurately was highlighted.

The paper is a pivotal step toward realizing comprehensive 6G access infrastructures, promoting interdisciplinary collaboration in advancing ARAN technologies further. The research provides strong directive insights for both academic exploration and industrial applications, advocating a robust foundation for the evolution of next-generation communication systems.

This paper sets a crucial precedent in integrating aerial networks within the broader 6G framework, fostering innovative solutions to long-standing connectivity challenges. As the communication landscape continues to evolve, such insights and technological advancements will prove indispensable in defining the future of global communications.