challenges of 5g ultra reliability - ieee · 2019-09-27 · huawei technologies co., ltd. 3 typical...

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HUAWEI TECHNOLOGIES CO., LTD.

Challenges of 5G Ultra Reliability

Li DehanHUAWEI RAS Technical Expert

ETR -RT 2018

HUAWEI TECHNOLOGIES CO., LTD. 2

Contents

What is 5G Ultra-high Reliability 1

Challenges of 5G Ultra-high Reliability2

Q&A4

Solutions for 5G Ultra-high Reliability3


Typical Usage Scenario for 5G

Sources： ITU-R: IMT Vision – Framework and overall objectives of the future development of IMT for 2020 and beyond. Recommendation.(09/2015),

URLLC scenario will bring big change for telecom network architecture.

Ultra-reliable is the basic requirement for entering mission critical

vertical industry.


Vertical Industry Requirements

Use Case Requirement text

Factories

of the

Future

Motion control

The 5G system shall support communication service availability exceeding at

least 99.9999%, ideally even 99.999999%.

The 5G system shall support UE speeds up to 20 m/s, even for

communication services with ultra-low latency and ultra-high reliability.

The cyclic data communication service of the 5G system shall be able to

support satisfy the safety requirements according to[＊] for safety integrity

level 3 (SIL-3).

Control-to-control

communication (motion

subsystems)

The 5G system shall support communication service availability exceeding at

least 99,9999%, ideally even 99,999999%.

The cyclic data communication service of the 5G system shall be able

support to satisfy the safety requirements according to [＊] for safety integrity

level 3 (SIL-3).

Mobile control panels with

safety functions

The 5G system shall support a communication service availability exceeding

at least 99,9999%, ideally even 99,999999%.

Process automation –

process monitoring

The 5G system shall support a communication service availability of about

99,99 % with a data transmission in intervals between 50 ms up to several

seconds.

Sources：3GPP TR 22.804 V1.0.0，Study on Communication for Automation in Vertical Domains ＊：IEC 61784-3: "Industrial communication networks – profiles – part 3: functional fieldbuses – general rules and profile definitions", 2016

Vertical industry like Factory of the future has ultra-high reliability ,

ultra-high availability, and SIL3 (PFH < 10−7/h) safety requirement.


Sources: Petar Popovski, Research Challenges towards Ultra--Reliable Wireless Communications

Many research target on packet loss rate of radio interface

Packet duplication [Popovski] ＊

Multi-connectivity [Fettweis]

Diversity-oriented approaches

Ultra-reliable of Radio Interface

＊ Mehdi Bennis, Building the foundations of Ultra-Reliable and Low Latency wireless communication.


5G Network Reference Structure

Automotive / Factory slicing will have edge cloud in the network, we

will have big problem to ultra-reliable requirements

Sources: View on 5G Architecture (Version 2.0)


• Human error• Software defect• Silence Failure• Overload problem

• COTS hardware • Virtualization layer• Openness/Dynamic• Cross Layer fault localization

• Radio ultra reliability• E2E Service ultra availability• Slicing fault isolation• Service defined availability

5G URLLC

Telecom Cloud

Telecom Box

Challenge of 5G Ultra-high Reliability

For target 5G Ultra reliability, we need to reach telecom grade cloud

reliability at first.


DFR in Cloud

Telecom cloud has same cloud native architecture with public cloud,

but all the DFR technology need to be enhanced to meet the telecom

grade reliability requirement.

DFR

Fault

ManagementArchitecture

Overload

Control

Hitless

Upgrade

Stateless VNF

Distribute DB

LB Pool

Fault detection

Fault localization

Self-healing

Fault isolationRedundancy

DFR: Design For Reliability

Fault prevention

Multi-DC/Region

Service

Degradation

Service Rejection

Auto scale in/out


Fault Detection: DeCentralized HA (DCHA)

COTS failure is normal，DON’Tlet it make service interruption become normal.

Decentralized Failure Detection

Fast fault detection is the basic feature for guarantee telecom grade

reliability.

VM Cluster Failure detection time 10+s or even 30+s, will cause service interruption

(call drops ).

COTS & large scale will make failures more frequently, then service interruption(call

drops) worsen much more.

DCHA supports sub-second VM failure detection.

Centralized Failure Detection


Self-healing: Fault Intelligent Self-Healing (xFISH)

Intelligent self-healing service provides best self-healing strategy, can

support Zero Touch fault management in Cloud.

UE

NFVI

UE

Network

Local Intelligent Self-healing

RAN 1


RAN 2


SDN Controller


5G Core VNF

Central Intelligent Self-healing

XFISH System in Telecom Cloud


0

2

4

6

8

10

12

14

16

18

Temporal

Spat

io

tttt RSTM

tM

tT

tS

tR

Data

MiningFailure Analysis

• 20% failures 80% business impact

• Hard to detect, diagnose and recovery

COTS/Decoupling/Virtualization of NFV will make it worse and more challenging

Silent

Failure

Gray

FailureFalse Alarm

COTS,Decoupling

Fast prevention: DM Failure Analysis for gray failure

prediction (DMFA)

Sick but not dead

“Gray Failure: The Achilles’ Heel of Cloud-Scale Systems”Peng Huang, Chuanxiong Guo, Lidong Zhou, etc， HotOS ’17

The fault of hardware which has life limitation (hard disk) can be predicted.

System degradation also can be predicted.


Fault Localization: Converged Localization Flow-

based ML (CLFM)

Cross Layer Reliability

Fault Localization

Active Probing

Automated

Correlation Analysis

VM VMVM VM

Key Enabling Technologies

≥ 90% < 1s

Cross layer fault localization is one of the biggest challenge in the NFV.

CLFM uses Hierarchical unsupervised machine learning to localize typical

fault in the NFV cloud in one second.


Overload Control: Intelligence OverLoad Control in

cloud (IOLC )

Predict the service change, automatic scale out to avoid overload in the cloud

OLC inside VNF must guarantee the VNF can survive before automatic scale out.

If the resources in the pool is limited, IOLC can borrow resources for overload VNF

form other VNF which is not busy.

Pool

VNF1 VNFi VNFn

IOLC

VM1 VM1 VM2VM3

(halt) VM1 VM2 VM3VM4

(new)VM2 VM3

OLC OLC OLC

IOLC in a Resources Limited Cloud


From “5 9s “to “6 9s” and SIL 3

Telecom Cloud Safety Critical＊

Software HA

Architecture

and

Technology

• Stateless VNF

• Distributed Database

• LB Pool

• All Active Disaster Recovery

• DCHA

• XFISH

• DMFA

• IOLC

• CLFM

• VM/Container Fault Isolation

• Grey Upgrade

• FMEA/FTA

• Fault Detection & Diagnosis

• Error Detecting Codes

• Diverse Monitor

• Functionally Diverse Redundancy

• Stateless Software

• Graceful Degradation

• Static Resources Allocation

• Semi-formal Methods

• Formal design and refinement Methods

• Event tree analysis

• Fault tree analysis

• Software functional failure analysis

＊IEC 61508-3 Functional safety of electrical/electronic/programmable electronic safety-related systems –Part 3: Software requirements

But how to reach ultra high availability and SIL 3? We still need to

borrow some ideas from safety critical industry.


E2E Channel Redundancy

Borrow ideas from safety critical industry (TMR/NVP/Voting)

E2E channel redundancy is one choice to guarantee E2E service

high availability, ms level switchover is the first step.

E2E Channel redundancy in 5G network

UE

RAN Channel 1

RAN Channel 2

User Plane

Channel 1

User Plane

Channel 2

Control Plane

Critical App Server

5G Core


Different reliability and availability for different slicing, Not Built to Peak

Different slicing has different network resources allocation strategy.

Different slicing has different HA service in cloud.

UE

5G RAN 3

5G RAN 4

UE5G RAN 1

5G RAN 2

5G Core 1

5G Core 3

UE

UE

Basic HA Service Basic HA Service

Higher HA Service

Higher HA Service

5G Core 2

Higher HA Service

Ultra HA Service

Ultra HA Service

Slicing 1

Slicing 2

Slicing 3

Service Defined Availability (SDA) for 5G slicing

5G Core 5

Ultra HA Service

5G Core 4

Ultra HA Service

SDA (Service Defined Availability) for different slicing


Ultra high reliability/availability and SIL 3 safety

requirements bring challenges for telecom industry.

“5 9s” reliability of telecom cloud is the foundation of 5G

ultra high reliability/availability.

Ideas form safety critical industry can be borrowed for 5G,

but cost is the big problem.

AI is the interesting direction for increasing the 5G ultra

high reliability/availability.

Conclusions

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The information in this document may contain predictive statements including, without limitation,

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technology, etc. There are a number of factors that could cause actual results and developments to

differ materially Sources those expressed or implied in the predictive statements. Therefore, such

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challenges of 5g ultra reliability - ieee · 2019-09-27 · huawei technologies co., ltd. 3 typical...

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