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NG-RAN and 5G-NR
5G Radio Access Network and Radio Interface
Frédéric Launay
First published 2021 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.
Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:
ISTE Ltd
27-37 St George’s Road
London SW19 4EU
UK
John Wiley & Sons, Inc.
111 River Street
Hoboken, NJ 07030
USA
© ISTE Ltd 2021
The rights of Frédéric Launay to be identified as the author of this work have been asserted by him in accordance with the Copyright, Designs and Patents Act 1988.
Library of Congress Control Number: 2021935849
British Library Cataloguing-in-Publication Data
A CIP record for this book is available from the British Library
ISBN 978-1-78630-628-9
Preface
This book aims to describe the deployment of 5G-NSA and 5G-SA.
For the 5G-NSA mode, dual MR-DC connectivity is based on radio measurements allowing the master 4G base station MeNB to add or to remove a 5G secondary node SgNB.
For the 5G-SA mode, the mobile is attached to the 5G core network. Even though this book is devoted to the radio access network, the mobile registration, establishment procedures and re-establishment procedures are also explained.
This book describes the architecture of the NG radio access network and the 5G-NR radio interface according to 3GPP (3rd Generation Partnership Project) specifications.
The 5G-NR radio interface was introduced in Release 15 of the 3GPP standards.
The 5G-NR radio interface is the interface between the UE mobile (User Equipment) and the 5GC mobile network (5G Core).
Chapter 1 presents the 5G-NSA and the 5G-SA deployment architecture. It describes the radio access entities and functions of the 5G-SA core network and presents the functions supported by the radio access and the 5GC core network.
In order to prepare RAN virtualization, the radio protocols of the gNB entity are supported by two units: a centralized unit and a distributed unit. This separation creates new interfaces called F1 on the radio access.
Chapter 2 presents the interfaces between the entities of NG-RAN radio access. It describes the protocol architecture on the Xn interface, the NG interface and the F1 interface, as well as the procedures for managing the interfaces of the NG-RAN network.
Similar to 4G CUPS (Control User Plane Separation) evolution, the 5GC network architecture separates the control plane to the user plane. The 5G-NSA and the 5G-SA architectures will be described by detailing interfaces and applications between the radio access entities and between the radio access and the network core (NG interfaces).
Chapter 3 presents general procedures for 5G-NSA and 5G-SA modes. It describes the procedures on the radio access network concerning the cell search, the bearer establishment, the mobility management, the management of the secondary node, the beam management, as well as the procedures to the core network such as attachment and session establishment.
5G-NR spectrum allocation is more flexible compared to 4G LTE. In the time domain, frame flexibility is improved with the introduction of new numerologies. In the frequency domain, flexibility is achieved with bandwidth partitioning allocated to the terminals.
In order to avoid future development constraints, the
