Future Generation Non-Terrestrial Networks

Dear Colleagues,

The Sixth Generation (6G) is being designed to meet the ever more stringent network requirements posed by emerging services, i.e., ultra-low latency, extreme capacity, high efficiency, and strong reliability.

In this context, the Future Generation Non-terrestrial Network (NTN) may be an excellent candidate to provide 6G services. Indeed, the interest in space communications and the Internet of Space Things (IoST) has significantly grown with the aim to provide access to any service anytime and anywhere owing to the broad coverage area or to satellite constellations that ensure global connectivity.

Future Generation NTN ensures service continuity of Machine-to-Machine (M2M)/Internet of Thing (IoT) devices or to people traveling on board moving platforms and service availability in case of both critical communications and future transmissions (i.e., maritime, aeronautical, railway). Furthermore, Future Generation NTN is expected to be an efficient solution to enable network scalability owing to the provision of multicast/broadcast resources for the delivery of data to network edges and user terminals.

NTN integration within the 6G wireless ecosystem is essential to ensure service availability, continuity, ubiquity, and scalability. The deployment of a unified wireless system including both terrestrial and NTNs allows for global connectivity that could be facilitated by the exploitation of the same radio technology. Therefore, the main NTN aspects to deal with are: (i) propagation delay, (ii) propagation channel, (iii) Frequency Plan and Channel Bandwidth, (iv) Link budget, (v) cell pattern generation, (vi) NTN platform mobility, and (vii) NTN terminal mobility.

NTN security is another challenging issue since NTNs are vulnerable to adversaries and malicious attacks. In fact, Future Generation NTNs are likely to handle large amounts of personal and sensitive data. Protecting the privacy of user information is critical to prevent unauthorized disclosure or misuse. Network operators must employ strong data encryption techniques, implement privacy-enhancing technologies, and adhere to strict data protection regulations to safeguard user privacy. The encryption algorithms used in these networks must also be robust and resistant to the quantum computing threats that are expected to characterize future 6G scenarios. In addition, strong authentication mechanisms are needed to verify the identity of devices connected to the network and prevent unauthorized access to the network. Addressing these security issues requires a multi-layered approach, including robust cryptography, authentication protocols, intrusion detection systems, secure satellite design, and cooperation among multiple stakeholders, including network operators, government agencies, and international organizations. Continued research and collaboration are critical to keeping up with emerging threats and ensuring the security and resilience of Future Generation NTNs.

Finally, Future Generation NTN shall leverage the following 6G key enablers: Terahertz (THz) communications, Optical Wireless Communication (OWC), Intelligent Reflecting Surfaces (IRS) or Reconfigurable Intelligent Surfaces (RIS), Cloudification, Blockchain, and Network and service orchestration and management.

This Special Issue aims to gather new solutions, procedures, methodologies, developments, applications to enable NTN in 6G.

In this Special Issue, original research articles and reviews are welcome. Research areas may include (but not limited to) the following:

• 6G standardization for Future Generation NTN.
• NTN trends and issues.
• NTN mobility and handover management.
• Space-Air-Ground communications.
• NTN architecture enhancements.
• Inter-satellite communications.
• NTN radio resource management and optimization.
• QoS management for Future Generation NTN.
• Multimedia broadcast/multicast delivery in Future Generation NTN.
• Adaptive beamforming and beam management for Future Generation NTN.
• Delay tolerant networking protocols for Future Generation NTN.
• NTN channel modeling.
• Internet of Space Things.
• Free space optical wireless communications.
• Security and privacy issues in Future Generation NTNs.
• Data privacy and security protocols for Future Generation NTN.
• Artificial Intelligence and Machine Learning for Future Generation NTN.
• Experiments, simulations, and modeling for Future Generation NTN.
• Terahertz communications for Future Generation NTN.
• Cloudification and Virtualization in Future Generation NTN.
• Network and service orchestration and management in Future Generation NTN.

We look forward to receiving your contributions.

Dr. Federica Rinaldi
Dr. Chiara Suraci
Dr. Helka-Liina Määttänen
Guest Editors

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• 6G
• NTNs
• satellite communications
• IoST
• NTN Security
• data privacy and security protocols for NTN