T3: 5G New Radio (NR) Protocols and Architecture

Presented by: Icaro Leonardo Da Silva, Gunnar Mildh, Paul Schliwa-Bertling, and Magnus Stattin (Ericsson Research)

Time: 9:00–12:30
Room: Milo 2

Abstract—In this tutorial the authors explain the fundamentals of the 5th Generation (5G) New Radio (NR) protocols and architecture, recently standardized by the 3rd Generation Partnership Project (3GPP). The focus of the tutorial is on the higher layer protocols (i.e. almost everything on the radio network, except the physical layer). More emphasis will be given to the Radio Resource Control (RRC) protocol, which is the protocol responsible for fundamental functions in the user equipment (UE) such as state model (e.g. IDLE, CONNECTED, INACTIVE states), connection control procedures (e.g. state transitions like IDLE to CONNECTED, INACTIVE to CONNECTED, etc.), measurement configuration and reporting (different types of measurements the UE performs, impact due to beamforming, etc.), mobility, dual connectivity with 4G (first version of the 5G standard), etc.

Tutorial Objectives
In the next few years we expect the development of algorithms and optmizations proposed by the research community based on 5G NR from 3GPP standards. Hence, the understanding of the recently standardized 5G NR protocols, which is the objective of the tutorial, is essential for the research community.

The tutorial held by 5G RAN protocol experts explains the fundamentals of the 5th Generation (5G) New Radio (NR) protocols and architecture. The main focus is on the higher layer protocols (i.e. almost everything on the radio network, except the physical layer). More emphasis will be given to the Radio Resource Control (RRC) protocol, which is the protocol responsible for fundamental functions in the user equipment (UE) such as state model (e.g. IDLE, CONNECTED, INACTIVE states), connection control procedures (e.g. state transitions like IDLE to CONNECTED, INACTIVE to CONNECTED, etc.), measurement configuration and reporting (different types of measurements the UE performs, impact due to beamforming, etc.), mobility, dual connectivity with 4G (first version of the 5G standard), etc.

Tutorial Outline
The tutorial will be divided in three parts. The first part of the tutorial will be on the overall 5G architecture, including the different options being standardized and the envisioned deployments for each of these options. That part will include an explanation of two main alternatives: Evolved Universal Terrestrial Network (EUTRAN) – New Radio (NR) Dual Connectivity (EN-DC), where E-UTRAN connected to Evolved Packet Core (EPC) serves as anchor for NR carrier frequencies, so the UEs uses Dual Connectivity with a 5G carrier. This part is divided as follows: – Fundamentals of 5G architecture – EN-DC architecture – 5G NR Standalone Architecture The second part is an overview of 5G NR protocols. That contains a discussion of some design choices in NR compared to LTE e.g. due to some specific challenges such as the need to be deployed in higher frequencies (such as in mmWave frequencies), the extensive use of beamforming, and the need to address a diversity of use cases from very low latency, to machine type devices. This part is divided as follows: – Overview of Physical layer (PHY) – Overview of Medium Access Control (MAC) – Overview of Radio Link Control (RLC) – Overview of Packet Data Convergence Protocol (PDCP) – Overview of Radio Resource Control (RRC) In the third part, the authors do a deep dive on control plane procedures specified in the RRC protocol (3GPP TS 38.331) [3], in particular some details concerning the design of the RRC INACTIVE state, as proposed by the authors in [4]. Here is where the authors expect to spend half of the time of this tutorial. This part consists of the following topics: – RRC state model (CONNETED, IDLE and INACTIVE states) – IDLE to CONNECTED transition (e.g. what happens when the UE is turned on, etc.) – CONNECTED to IDLE transition (e.g. what happens when the UE stops transmitting/receiving data, etc.) – INACTIVE state introduced in 5G NR (e.g. properties, advantages compared to IDLE, RAN paging) [4] – INACTIVE to CONNECTED transition (resume procedure) – CONNECTED to INACTIVE transition (suspend procedure) – CONNECTED measurement configuration and measurement reporting – Reestablishment and Reject – Mobility procedures – Dual Connectivity procedures

Primary Audience
Researchers, students, engineers, and research leaders from industry or academia interested to learn and discuss the fundamental aspects of 5G New Radio (NR) architecture and protocols recently standardized in 3GPP. We also expect the audience to highlight aspects that could be later improved in the future.

Novelty
This tutorial is an unique opportunity for atendees.

First of all, 5G NR standards have just been completed and comercial deployments are expected in 2019. Hence, we expect many conference atendees to be interested in the tutorial as there could not be in better time.

Second, it is a chance to interact with industry experts on 5G NR protocols and architecture standardized by 3GPP. They have been involved in early 5G research external and internal projects, and actively participated in 5G standardization.

Third, there is currently a lack of material/books on tutorial format on 5G NR architecture and protocols.

Biography
Icaro Da Silva received his M.Sc. in electrical engineering from the Universidade Federal of Ceara (UFC), Fortaleza, Brazil in 2009. In 2010, he joined Ericsson Research, Ericsson AB, Stockholm, and has since been working on standardization and concept development for LTE and 5G NR, in particular driving control plane topics in 3GPP RAN2. He has also worked as a 3GPP delegate in RAN2 and actively participated in the draft of the 5G NR RRC specifications (TS 38.331). His focus areas has been on 5G NR radio network architecture and protocols, in particular the control plane design and RRC protocol. Icaro has lead the 5G control plane in the EU project on 5G RAN architecture METIS-II, part of the 5G-PPP framework. He has also participated as panelist on 5G design and 5G architecture in VTC and EuCNC. He is currently a senior researcher in radio network architecture and protocols, Ericsson Research.

Magnus Stattin graduated and received his Ph.D. degree in radio communication systems from the Royal Institute of Technology, Stockholm, Sweden in 2005. He joined Ericsson Research in Stockholm, Sweden, in June 2005. At Ericsson Research he has been working with research in the areas of radio resource management and radio protocols of various wireless technologies. He is active in concept development and 3GPP standardization of LTE, NB-IoT, NR and future wireless technologies.

Gunnar Mildh received his M.Sc. in electrical engineering from the Royal Institute of Technology (KTH), Stockholm, Sweden, in 2000. In the same year, he joined Ericsson Research, Ericsson AB, Stockholm, and has since been working on standardization and concept development for GSM/EDGE, HSPA, LTE(-A) and 5G NR. His focus areas has been on radio network architecture and protocols, and recently on 5G architecture including RAN and Packet Core. He is currently an expert in radio network architecture at Ericsson Research.

Paul Schliwa-Bertling received his B.Sc. in electrical engineering from the University of Duisburg-Essen, Essen, Germany. He joined Ericsson Research, Ericsson AB, Stockholm, and has since been working on standardization and concept development for GSM/EDGE, HSPA, LTE(-A) and 5G NR. He has also worked many years as a 3GPP delegate in SA2. His focus areas has been on radio network architecture and protocols, and recently on 5G architecture including RAN and Packet Core. He is currently an expert in mobile network architecture and signaling at Ericsson Research.