5G NR Non-Terrestrial Networks: Open Challenges for Full-Stack Protocol Design

TL;DR

This paper discusses the integration of non-terrestrial networks into 5G NR, highlighting key protocol design challenges across the full stack and presenting initial ns-3 simulation results.

Contribution

It identifies critical challenges in full-stack protocol design for 5G NR-NTN, focusing on satellite communication aspects and providing initial simulation insights.

Findings

Highlighting PHY, MAC, and upper layer challenges

Simulation results show impact of challenges on network performance

Initial steps toward 3GPP 5G NR-NTN standardization

Abstract

As 5th generation (5G) networks continue to evolve, there is a growing interest toward the integration of Terrestrial Networks (TNs) and Non-Terrestrial Networks (NTNs). Specifically, NTNs leverage space/air base stations such as satellites, High Altitude Platforms (HAPs), and Unmanned Aerial Vehicles (UAVs) for expanding wireless coverage to underserved rural/remote areas, supporting emergency communications, and offloading traffic in highly congested urban environments. In this paper we focus on the 3GPP 5G NR-NTN standard in the context of satellite communication networks, and highlight critical challenges that must be addressed for proper full-stack protocol design, with considerations related to the PHY, MAC, and higher layers. We also present simulation results in ns-3 to demonstrate the impact of some of these challenges on the network, as an initial step toward more advanced standardization activities on 3GPP 5G NR-NTN.