3GPP Non-Terrestrial Networks Overview

CONTENTS

This course presents an overview of the non-terrestrial (eg satellite-based) communication option for 5G and 4G networks as specified by 3GPP.

Satellite communications introduction is followed by NTN architecture for 3GPP networks. Some of the challenges for non-terrestrial communication are mentioned and followed by a description of a number of changes and enhancements added to 3GPP standards to facilitate the satellite-based communication.

PREREQUISITES

Technical knowledge of mobile telecoms, especially the 5G and 4G networks, is strongly recommended.

Introduction

• Satellite communication background
• Selected satellite communications applications
• Communication orbit types and characteristics

Architecture of 3GPP NTN

• ITU-R requirements for satellite component of IMT-2020
• 3GPP introduction and 3GPP NTN history
• 3GPP NTN applications and benefits
• 3GPP NTN standardization in Releases 17 to 19
• 3GPP system requirements for satellite access
• 3GPP NTN architecture - introduction
• NTN cells: Earth-fixed, quasi-Earth-fixed, Earth-moving
• Rel-17 transparent NTN architecture
• Rel-19 regenerative NTN architecture
• NTN based NG-RAN
• Additional configuration parameters for NTN RAN
• UE requirements in NTN communication
• UE types for satellite communication

Communication Challenges

• Satellite radio communication issues
• Mobility of LEO and MEO satellites
• Issues due to large propagation delays
• Atmospheric absorption
• Cells and Tracking Areas handled by moving satellites
• Cells with large coverage area - regulatory issues

System Enhancements

• Summary of 3GPP system enhancements for NTN communication
• Frequency bands for NTN communication
• Timing Advance handling
• Doppler effect handling
• New RAT types
• Handovers to/from/between NTN cells
• Dual connectivity options
• HARQ modifications
• Discontinuous coverage support
• UE location verification
• AMF node selection and re-selection
• New 5QI and CQI values
• Earth-fixed cells and Tracking Areas
• Satellite switch with re-synchronization
• Feeder link switchover
• UE-Satellite-UE communication for IMS voice and video
• Store-and-Forward for satellite IoT