Uwe Herzog

EURESCOM

EuCNC Panel on OpenRAN, 16/06/2020

Challenges for Network Slicing

in O-RAN

Based on work done in 5G-DRIVE

5G-DRIVE in a nutshell

5G DRIVE aims to bridge current 5G developments in Europe and China through joint trials and research activities in order to facilitate technology convergence, spectrum harmonisation and business.

30-month (September 2018 – February 2021) Research and Innovation Action project, funded under the Horizon 2020 Framework programme.

17 partners from 10 European countries (Germany, Finland, Belgium, Italy, Switzerland, Poland, Greece, Portugal, United Kingdom and Luxembourg).

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5G-DRIVE Consortium

5G Product Large-Scale Trial Consortium

eMBB V2X

Spectrum Usage Techn

ical In

no

vation

Join

t Trials

Slicing SDN

/NFV

V2

N

V2

V

Common 5G KPIs

5G

NR

MEC

Arch

itectu

re Security

Status at 3GPP concerning RAN slicing

3GPP 5G SA allows for dynamic creation of separate logical networks, known as network slices

3 basic network slice classes have been defined: URLCC, eMBB, mMTC

Affects both 5GC and RAN

Basic principles concerning RAN slicing are established in 3GPP, but no plans for defining how to implement RAN slicing

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Slice Type Bandwidth Latency Reliability Connection

density

eMBB 20 Gbps (DL) 10 Gbps (UL)

10 ms - -

URLLC - < 1 ms 99.9999% -

mMTC - < 10 s - 1 M/km2

Status of RAN slicing at O-RAN Alliance

O-RAN Alliance approach of „openness“, disaggregating eNB/gNB into multiple modules with defined standard interfaces appears very attractive Enabling multi-vendor, best of breed flexibility

Move away from proprietary hardware to off-the -shelf general purpose platforms

Allows leveraging the Open Source community

Greater agility, enables faster innovation

Reduces complexity

lowers CAPEX/OPEX

But Only few documents on slicing released by O-RAN Alliance so far

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5G-DRIVE Cooperation with Chinese twin project

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Several O-RAN related topics have been chosen for cooperation, including work on RAN slicing and the feedback-loop based control over E2 interface.

First concepts for slicing extensions to O-RAN have been proposed by 5G-DRIVE and shared with the Chinese twin project

NB: Significant (overall) research on RAN slicing already done in the community, with various concepts proposed.

EuCNC Panel on OpenRAN, 16/06/2020

Challenges for O-RAN Slicing

Even though RAN slicing not implemented in O-RAN currently, the platform seems a very promising solution

Little „guidance“ from 3GPP and O-RAN Alliance on RAN slicing implementation

Difficult to involve verticals (due to complexity) to capture requirements

Significant changes to the current O-RAN architecture required

modification of MAC to support scheduling of different traffic types (eMBB, URLLC, etc.)

A different split for different slice types

customization of the RRM to obtain per slice behaviour as complementary mechanism to scheduler (packet scheduling, admission control)

proactive provisioning of appropriate radio coverage and radio link quality on a per slice type level by using R-NIB and slice information.

partitioning of the Application Layer of the near-RT RIC to separate slice operation spaces and their privileges and restrictions

Support for multiple verticals at the Application Layer of the near-RT RIC

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NS Enabled O-RAN - concept principles

Near-RT RIC functions are sliced in the way in which all its functional elements (e.g. QoS Management, Radio Connection Management) are partitioned and each slice has full constellation of these partitions composing the „virtual RIC” dedicated to the slice and connected with the „master RIC”.

The components are piggy-backed to the main component that realizes the function, for example Main Mobility Management Application

The Coordinator (AI-driven) is trying to increase the orthogonalization’ of APP requests

Each slice has isolated R-NIB partition relevant only to this slice (i.e. about UEs that are attached only to this slice)

Easy integration with updated MEC is possible

F1

O-RU: PHY-low/RF

NFVI Platform: Virtualization layer and COTS platform

E2: between RIC near-RT and CU/DU

Open Front Haul

O-DU

MAC/PHY-high

RLC/MAC

Multi-RAT CU protocol stack

CU-UP

PDCP-U

SDAPCU-CPRRC

PDCP-C

Orchestration & Automation (e.g. ONAP): MANO, NMS

Design Inventory Policy Configuration RAN Intelligent Controller (RIC) non-RT

A1

Network Slicing-Enabled RAN Intelligent Controller (RIC) near-RT

Applications Layer

APPRadio Conn.

MgmtMob. Mgmt

Int. Mgmt

QoS Mgmt

Radio-Network Information Base

RNIB slice#1Slice #1

RNIB slice#2Slice #2

RNIB slice#3Slice #3

O-SONCoordinator

E1

7

EuCNC Panel on OpenRAN, 16/06/2020

Several joint whitepapers planned by 5G-DRIVE and Chinese twin project

RAN slicing survey

RAN slicing enabled near real-time RIC

O-RAN near real-time RIC functions coordination

Thank you for your attention!

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Find us at www.5g-drive.eu

Twitter: 5gDrive

Acknowledgment: The research conducted by 5G-DRIVE receives funding from the European Commission H2020 programme under

Grant Agreement No 814956. The European Commission has no responsibility for the content of this presentation.

EuCNC Panel on OpenRAN, 16/06/2020