Towards 6G Non-Terrestrial Networks

TL;DR

This paper explores the integration of Non-Terrestrial Networks into 6G, analyzing 3GPP standards, identifying challenges for New Radio in NTNs, and providing insights for future research to enable seamless 6G services.

Contribution

It offers a comprehensive analysis of 3GPP specifications for NTNs, highlighting constraints, strengths, weaknesses, and open issues for 6G NR-enabled non-terrestrial networks.

Findings

Identifies key constraints of NR in NTNs

Highlights strengths of NR for 6G services

Discusses open research challenges

Abstract

Sixth-Generation (6G) technologies will revolutionize the wireless ecosystem by enabling the delivery of futuristic services through terrestrial and non-terrestrial transmissions. In this context, the Non-Terrestrial Network (NTN) is growing in importance owing to its capability to deliver services anywhere and anytime and also provide coverage in areas that are unreachable by any conventional Terrestrial Network (TN). The exploitation of the same radio technology could greatly facilitate the integration of NTNs and TNs into a unified wireless system. Since New Radio (NR) is the de facto standard to deliver manifold heterogeneous services in terrestrial wireless systems, 3GPP is investigating new solutions to extend NR to NTNs. In this paper, the constraints that NTN features place on NR procedures are investigated by going thoroughly into 3GPP specifications; strengths and weaknesses of the NR technology in enabling typical 6G services on NR-enabled NTNs are identified; finally, open issues and insights are provided as guidelines to steer future research towards 6G NTNs.