5g mobile network testing

5G MOBILE NETWORK TESTING

Rohde & Schwarz Mobile Network Testing

Jibran Siddiqui

Technical Manager

Rohde & Schwarz

CONTENTS

11/15/2020 5G MOBILE NETWORK TESTING2

• 5G market drivers and key challenges

• Status about frequency bands globally for 5G

• Introducing the 5G Network Architectureo Stand Alone

o Non-standalone

• 5G technologies and features

• Comparing 5G to 4G

• Coverage and Quality parameters

• Interference mitigationo Spectrum Clearance

o Interference Hunting basics

• 5G network testing solution highlightso Flexibility with scanners in mmWave and LTE/5G NSA

measurements

o Measurements with ROMES

Rohde & Schwarz3

5G IS ALREADY GLOBALLY PRESENTCOMMERCIAL SERVICES ARE LAUNCHED

Source: GSA report: Evolution from LTE to 5G: Global Market Status, August 2020

► 397 operators in 129 countries are investing in 5G (launches, demos, trials)

► 96 operators in 41 countries announced 3GPP 5G full commercial

service launches (118 operators in 59 countries activated 5G sites

within their live commercial networks)

► 12 operators have or will launch

5G Standalone in 2020

► Just the August 2020 snapshot:

figures are growing constantly

11/15/2020 5G MOBILE NETWORK TESTING

Rohde & Schwarz

FREQUENCY TRENDS FOR 5G


NR frequency range 1

reserved numbers 65-256

Downlink Uplink

… … …

n77 3.3 – 4.2 GHz 3.3 – 4.2 GHz

n78 3.3 – 3.8 GHz 3.3 – 3.8 GHz

n79 4.4 – 5.0 GHz 4.4 – 5.0 GHz

… … …

NR frequency range 2

Reserved numbers 257-512

Downlink Uplink

n257 26.5 – 29.5 GHz 26.5 – 29.5 GHz

n258 24.25 – 27.5 GHz 24.25 – 27.5 GHz

n259 39.5-43.5 GHz 39.5-43.5 GHz

n260 37 – 40 GHz 37 – 40 GHz

Rohde & Schwarz

KEY CHALLENGES RELATED TO 5G NR RAN


New spectrum

ı Even 3.5 GHz is different from today’s frequencies

ı What about coverage?

ı Spectrum clearance?

Beamforming for Synch.

and Broadcast Signals

ı How does beamforming work?

Flexibility of air interface

and gNB configuration

ı Bandwidth: 5, 10, 15, 20, 25, 30, 40, 50, 60, 80, 90, 100 MHz (FR1)50, 100, 200, 400 MHz (FR2)

ı Subcarrier Spacing:15, 30, 60 kHz (FR1)60, 120, (240) kHz (FR2)

ı Mapping onto antenna ports: single beam / multi beam sweeping

➢ New technology elements drive the need for (and complexity of)

5G NR network measurements

Attenuation

Rohde & Schwarz

REVIEW OF 5G USE CASESeMBB REMAINS PRIORITY 1 BUT …


eMBB – the known playground

ı Established ecosystem (operators, manufacturers,

certification of devices)

ı Evolution from existing technologies and revolutionary

additions (cm- / mm-wave)

ı It’s all about data (speed and capacity)

ı Realizing and facing the challenges of cm-wave

spectrum and OTA testing; 3.5GHz is important!

URLLC

ı A significantly enhanced and

diverse ecosystem (operators (?),

manufacturers, verticals,

certification not existing (yet))

ı Principal support with high SCS

and self-contained slots

ı It’s all about reliability and security

(data and capacity)

massive Machine

Type Communication

Ultra reliable &

low latency

communication

enhanced Mobile

Broadband

eMBB

mMTC URLLC

Massive IoTı A diverse ecosystem

(operators, manufacturers,

local authorities, certification

only for some technologies)

ı Mix of technologies

(GSM, Lora, Zigbee, WLAN,

Bluetooth, Cat M, NB-IoT,…)

ı It’s all about cost efficiency

and massive connectivity

ı 3GPP: No NR based solution;

will be addressed by evolving

LTE-M (eMTC) and NB-IoT

Rohde & Schwarz

CONTENTS





o Non-standalone



• Coverage and Quality parameters




measurements


Rohde & Schwarz

5G NEW RADIO (NR) OFFERS A FLEXIBLE AIR INTERFACE SUMMARY OF KEY PARAMETERS

Parameter FR1 (410 MHz – 7.125 GHz) FR2 (24.25 – 52.6 GHz)

Carrier aggregation Up to 16 carriers

Bandwidth per carrier 5, 10, 15, 20, 25, 30, 40, 50, 60, 80, 90, 100MHz 50, 100, 200, 400 MHz

Subcarrier spacing 15, 30, 60 kHz 60, 120, 240 (not for data) kHz

Max. number of subcarriers 3300 (FFT4096 mandatory)

Modulation scheme QPSK, 16QAM, 64QAM, 256QAM; uplink also supports π/2-BPSK (only DFT-s-OFDM)

Radio frame length 10ms

Subframe duration 1 ms (alignment at symbol boundaries every 1 ms)

MIMO scheme Max. 2 codewords mapped to max 8 layers in downlink and to max 4 layers in uplink

Duplex mode TDD, FDD TDD

Access scheme DL: CP-OFDM; UL: CP-OFDM, DFT-s-OFDM


LTE

Rohde & Schwarz

ARCHITECTURE OPTIONSOPTION 3 IS PRIORITY 1 IN 3GPP, FOLLOWED BY OPTION 2


EPC

eNB

(LTE)

gNB

(5G)

MME SGW

Option 3:Non-Standalone

Data

Control

Option 2: Standalone

NGC

AMF UPF

gNBeNB is the

Master Node

MME = Mobility Management Entity

S-GW = Serving Gateway

AMF = Access and Mobility Management Function

UPF = User Plane Function

gNB is the

Secondary Node

EN DC: E-UTRA-NR

Dual Connectivity

Rohde & Schwarz

HOW CAN A UE IDENTIFY A 5G CARRIER?


Carrier BW

BWP 1 BWP 2 BWP 3

SS

B

SS

B

SSB = SS/PBCH block

First action of UE looking for 5G cell: search for Synchronization Signals

ı One SSB is always transmitted → the only Always-On signal in 5G NR!

ı The 5G NR UE uses the SSB for ▪ Synchronization

▪ System information (MIB/SIB)

▪ Cell and Beam quality measurements

frequency

BWP: BandWidth Part:

contiguous subset of physical resource

blocks within the overall carrier bandwidth

of a certain frequency spectrum

Rohde & Schwarz

BANDWIDTH PARTS (BWP)

Motivation: Provide a flexible method to assign various numerologies to a device, thereby

adapting to different QoS requirements.


Up to four BWPs in DL/UL per UE:

ı Single BWP at a given time

(active BWP)

ı No reception of PDSCH or

PDCCH outside DL BWP

ı No Transmission of PUSCH

or PUCCH outside UL BWP

ı BWPs can be switched by RRC

(slow), DCI (fast) or based on

timers

Rohde & Schwarz

SS/PBCH BLOCKS = SSB

► Time domain:

SSB consists of 4 OFDM symbols, where

PSS, SSS and PBCH with associated

DM-RS occupy different symbols

► Frequency domain:

SSB consists of 240 contiguous

subcarriers

► Like in LTE the Cell ID can be determined

from the used PSS/SSS sequences

11/15/202012

Synchronization Signal Block = SSB

PSS: Primary Synchronization Signal SSS: Secondary Synchronization Signal

PBCH: Physical Broadcast Channel DM-RS: DeModulation Reference Signal

239

. . . . . .

192

. . . . .

182

. . . . .

56

. . . . .

47

. . . . .

9

5

1

0

DM-RS


Rohde & Schwarz

SSB AND DIFFERENT BEAMS – „BEAMFORMING“

► Demodulation of the PBCH → determines the SSB index and

→ distinguishes between the periodically broadcasted SSBs

► Each SSB can be mapped to a different group of antenna elements to transmit in a certain

direction

► Example: Case A with subcarrier spacing of 15 kHz and 8 SSB indices


…

Case A (15 kHz)

3 f 6 GHz (L=8)

0 1 2 3 4 5 6 7 Block index 0…Lmax-1

5 ms

Different beams / SSB indices

➢ Beamforming of synchronization signals and broadcast information via 5G NR SSBs

Rohde & Schwarz

SSB – IN SINGLE BEAM OR MULTI BEAM CONFIGURATION

Typical Use Cases:

► In-building deployment (office, stadium

concourse, shopping malls, etc.)

► Macro sites to improve data throughput

(stable data connection with low

interference and high MCS) and capacity

► Coverage extension (Synch Signals and

Broadcast Channel Info) to compensate

higher attenuation


Single Beam

Multi Beam sweeping

… …

… …

SSB

0

SSB

1

SSB

2

SSB

3

SSB

m… SSB

0

SSB

1

SSB

2

SSB

3

SSB

m……

SS burst 0 SS burst 1

time

➢ 5G NR network measurements need to cope with high flexibility and configurability

Rohde & Schwarz

5G NR: SIMPLE BEAMFORMING


Same PCI, different SSB indices

gNB uses SSBs to be mapped on

„static“ beams. PDSCH & PUSCH will

also follow SSB beam concept

Rohde & Schwarz

DYNAMIC SPECTRUM SHARING (DSS)

5G MOBILE NETWORK TESTING16 11/15/2020

Time

Fre

qu

en

cy What?

► Resource shared between LTE and

5G (e.g. 10 MHz in 850 MHz band)

► Dynamical changes of LTE or 5G

allocation per subframe (1ms)

Why?

► Smooth and faster rollout of 5G (than

refarming)

► Wide 5G coverage quickly, if low

frequencies are used

► Optimized resource usage depending

on LTE and 5G subscriber population

and requests

► But: capacity is limited due to

available spectrum in low bandsImage source: Ericsson

Rohde & Schwarz

CONTENTS





o Non-standalone



• Coverage and Quality parameters (Interactivity)




measurements


Key Performance

Indicators in 5G

5G MOBILE NETWORK TESTING18

❑ Coverage (traditional): ❑ RSRP, SINR, etc.

❑ Latency

❑ Round-trip latency

❑ One way latency

❑ Redundancy

eMBB: Augmented Reality (AR / VR)

► Interactive / round-trip latency is key → Interactivity test!

URLLC:

► Often one-way latency is important (e.g. robot control,

automated guided vehicles, remote controlled trolley, etc.)

Rohde & Schwarz

THE NEW INTERACTIVITY TEST – eMBB IS ROUND-TRIP

19

► Interactivity is the combination of Bitrate + Latency + Continuity!

► The device sends a UDP stream of unique packets to an (active) server that reflects it

► TWAMP: Two-Way Active Measurement Protocol – specified by IETF (RFC 5357)

(Traffic can be emulated; TWAMP defined for latency SLA verifications)

► Control parameters (on technical level) are:

− Packet rate

− Packet size

− Delay budget


► Results:

− Round-trip latency

− Packet delay variation

− Packet Error Rate

low

high

small

large

accepted delay

QualiPoc

Android

Ping

11/15/2020

Rohde & Schwarz

INTERACTIVITY SCORE – THE QOE MODEL

20

► For emulating ‘real’ applications we will apply a generic QoE model

► The QoE model produces a ‘synthetic’ MOS (Mean Opinion Score) based on QoS and techn. KPIs

► Interactivity Score

Interactivity Score = f1 (latency, time)


* f2 (delay variation) * f3 (packet loss)

► Interactivity Score combines latency, delay variation and packet loss into one single score

Pe

rfe

ct

To

lera

ble

Cri

tical

Fail

11/15/2020

Rohde & Schwarz

► This sort of generic QoE model is fully scalable

INTERACTIVITY TEST – a scalable concept for round-trip latency measurements


scalable

► The parametrization of the Interactivity Test and Score

is individual for each application class

► e.g. AR / VR Remote Support in Smart Factory

Robot control in the

smart factory?

11/15/2020

Rohde & Schwarz22

INTERACTIVITY TESTROUND-TRIP LATENCY MEASUREMENT

Network under test

(4G, 5G, WiFi, ..)

Measure and analyze round-trip latency on

QualiPoc Android using TWAMP reflector

(any TWAMP capable Internet node)

► Interactivity Test is commercially available in our QualiPoc Android solution offering

Rohde & Schwarz

CONTENTS





o Non-standalone







measurements


Rohde & Schwarz

IMPACT OF INTERFERENCE


5th Gen (5G) -120 dBm

NB-IoT -130 dBm

Rohde & Schwarz

0

100

200

300

400

500

600

700

800

-15 -5 5 15 25 35 45

Re

lativ

e t

hro

ug

hp

ut / %

SINR / dB

Example MCS vs. SINR

64QAM

(MCS 11...19)

256QAM

(MCS 20...27)

16QAM

(MCS 5...10)QPSK (MCS 0...4)

100

0

200

300

400

500

600

700

800

-5 5 15 25 35 45-15

WHAT IS THE IMPACT OF INTERFERENCE ON CAPACITY?

► Not easy to quantify

► Depending on many parameters

and implementation

The graph is a simplified real-world example for EPA5,

2x2MIMO and HARQ.

The MCS-SINR relation depends on the specific Base

Station vendors' algorithms, performance and

scheduler implementation, as well as on the channel

fading profile etc.

Rule of thumb:

10 dB less SINR

→ 50% less

data throughput

MCS: Modulation and Coding scheme

SINR: Signal to Interference and Noise Ratio

TAKEAWAY: Interference dramatically impacts network performance

→ Spectrum clearance in new spectrum becomes essential


Rohde & Schwarz

SPECTRUM CLEARANCE BEFORE OR AFTER DEPLOYMENTMASKING UPLINK WITH GATED TRIGGER

26 5G MOBILE NETWORK TESTING11/15/2020

Trigger Free Run

(Down Link

and Uplink)

Gated Trigger

(only Uplink)

Interference

Rohde & Schwarz

SPECTRUM CLEARANCE BEFORE OR AFTER DEPLOYMENTMASKING UPLINK WITH GATED TRIGGER

27 5G MOBILE NETWORK TESTING11/15/2020

Trigger Free Run

(Down Link

and Uplink)

Gated Trigger

(only Uplink)

Interference

Rohde & Schwarz

REAL FIELD MEASUREMENTS RESULTS AT 3500 MHz


Rohde & Schwarz

INTERFERENCE HUNTING AND SPECTRUM CLEARANCE


Application

ı Locating interferers

(indoor or outdoor)

ı Spectrum checking /

clearance

Rohde & Schwarz30

► Fast automatic direction-finder

with 600 DF measurements /

minute

► The first handheld correlative

interferometer direction-finder with

typ. 1 degree RMS system DF

accuracy on the world market

► Integrated GPS and electronic

compass

► Magnetic mount for quick and

easy DF antenna installation on a

vehicle roof

FAST AUTOMATIC DIRECTION-FINDING WITH MULTI-ELEMENT DF ANTENNA

Interference


Rohde & Schwarz31

EASY-TO-USE SOLUTION THAT LOCATES SOURCES OF INTERFERENCE

Customer comment:

“We were searching for an

interference without

success for 4 weeks.

With MobileLocator it took

30 minutes to locate it.”


Mobile Network Testing

Rohde & Schwarz

CONTENTS





o Non-standalone







measurements


Rohde & Schwarz

R&S TEST SOLUTIONS TO DEPLOY 5G NR NETWORKS


R&S®SmartONE(5G NR ONE tool for optimization, network benchmarking and engineering)

R&S®TSME6

R&S®TSMA6

5G NR network measurement solution

R&S®Freerider 4(FR1 and FR2)

Passive measurements Active measurements

5G router 5G smartphones

QualiPoc Android

Spectr. clearance / Interfer. hunting Data analytics

R&S®FPH 31GHz

R&S®MNT100 & PR200 R&S®MobileLocator

R&S®TSMA6 R&S®FSH

SmartAnalytics(software suite)

(TDD gated trigger)

Site troubleshooting & acceptance

QualiPoc AndroidR&S®5G STS R&S®FPH

Standard

mode

Expert

mode

Rohde & Schwarz

DIFFERENCE BETWEEN SCANNER AND MOBILE PHONE MEASUREMENTS


Measurement device

Measurement modePassive: just receiving,

no SIM required

Active: SIM-based connection to

its operator

Measurement accuracy Accurate (+/- 1dB) +/- 6dB

Measured cellsAll receivable cells (all operators,

all configured frequency bands)

Connected cell and neighbors

(limited), own operator

Measurement speed / frequency + -

Use case Reference RF measurement Real world, comparability

Solution: Scanner controlled

by QualiPoc Android

Rohde & Schwarz

5G NR NETWORK MEASUREMENT SOLUTION


SmartONE (expert mode / ROMES4):

5G NR Software for network engineering,

analysis and optimization

(running on laptop or NUC PC in TSMA6)

For comfortable

walk tests

➢ Industry’s first commercially available 5G NR network measurement

solution launched by Rohde & Schwarz Mobile Network Testing

TSME6: Ultra-compact network scanner

TSMA6: Autonomous network scanner

plus downconverter for 28 / 39 GHz frequency bands

Rohde & Schwarz

MAIN TAKE-AWAY –COVERAGE

► Expected UE sensitivity:

~ -120 dBm (SS-RSRP)

► Suburban area (3.7 GHz)

► Surprisingly good SSB

coverage

► Static SSB beamforming

allows for long radio range


-125dBm SS-RSRP

~ 6.5km distance

gNodeB

-110dBm SS-RSRP

-90dBm SS-RSRP

-100dBm SS-RSRP

✓

➢ Operators can try to reuse

site grid ?

Rohde & Schwarz

SSB / BEAMFORMINGVERIFICATION


Same PCI, different SSB indices

✓

► Best received SSB index /

beam visualized on the map

► Surprisingly good match with

horizontal “micro sectors”

(SSB beam indices)

► 3.7 GHz, sub-urban

environment

gNodeB

Rohde & Schwarz

„Massive beamforming“

can be evaluated

in the field

BEAMFORMING EVALUATION IN THE FIELD (28 GHz)

► One PCI

► Focus on best beam

(SSB index)

38 11/15/2020 5G MOBILE NETWORK TESTING

Rohde & Schwarz

TESTING DYNAMIC SPECTRUM SHARING IN THE FIELD

► Automatic Channel Detection showing DSS


R&S®TSMA6 (autonomous network scanner)

R&S®SmartONE expert mode ACD

11/15/2020

Rohde & Schwarz

FIRST UE-BASED 5G NR MEASUREMENTS


R&S®SmartONE expert mode

(ROMES4) GUI with 5G mobile device data

https://www.linkedin.com/feed/update/urn:li:activity:6488431089424564224

5G NR

Serving Cell

5G NR

Uplink

5G NR

Downlink

5G NR Cell

History

5G NR Cell

Quality

RSRP,

RSRQ

Tx Power

DL Thp

https://www.linkedin.com/feed/update/urn:li:activity:6488431089424564224

Rohde & Schwarz

FLEXIBILITY: MM-WAVE/SUB 6 GHz MEASUREMENT SETUPINCLUDING SCANNERS, SIMULTANEOUS MEASUREMENTS


Sub 6 / IFReal-timeswitching

TSME30DC/44DC

5GNR

mm-waveRF

LTE + 5GNR

sub-6 GHzRF

PC including

R&S®SmartONE

Drive Test Software

HW control

Downconverter

Local oscillator

R&S®TSME6

► single frontend!

Downconverter

IF

TSME30DC/44DC

5GNR

Local oscillator

RF

LTE + 5GNR RF

HW control

Further speed improvements

Standard performance setup

R&S®TSME6

R&S®TSME6

Alternative with R&S®TSMA6

and tablet for control

Rohde & Schwarz

SUMMARY OF R&S SCANNER ADVANTAGES


Performance:► mmWave and sub6 measurements with only 1 frontend

► mmWave frequencies up to 44 GHz

► Automatic Channel Detection (ACD) can run smoothly in the background

► Dynamic Spectrum Sharing (DSS) using a single frontend

► > 10 dB (!!!) higher receiver sensitivity in 5G than best competitor

► Far better dynamic range in 5G than best competitor

► Standard speed in mmWave and sub 6 GHz with just one frontend and one FR2 antenna

► Simultaneous LTE 2x2 MIMO and mmWave / sub6 5G measurements with two frontends (e.g. TSME6)

Flexibility:► Just add scanner for measurement speed improvement

► Every R&S 5G scanner can be upgraded to mmWave (FR2)

Future-proof:► Every R&S 5G mmWave scanner setup can be upgraded to 4x4 MIMO LTE

► Every R&S scanner setup can be upgraded to 4x4 MIMO LTE

Rohde & Schwarz

5G NR POST PROCESSING IN THE CLOUD

► Use-case driven analytics

► Cloud based or locally installed

► Aggregated data layers +

High resolution file data

► Intuitive filtering

► 5G NR Scanner Workspace

− Best Cell Coverage

− Best SSB Coverage

− NR vs 4G Coverage Comparison

− TopN Details


5G NR Scanner Analysis

in R&S®SmartAnalytics

Rohde & Schwarz

CONCLUSION


➢ Rohde & Schwarz MNT is committed to support the industry with network test

solutions from early trial phase to network optimization and benchmarking

Commercial 5G NR network measurement solution available by Rohde & Schwarz

5G NR network measurements need to cope with high flexibility, configurability and

complexity of new technology elements

Verification of coverage and SSB beamforming in many networks with R&S

5G NR commercial rollout running now – many pre-commercial trials!

Commercial 5G NR smartphones available on the market

https://www.rohde-schwarz.com/MNT-5G

https://www.rohde-schwarz.com/MNT/stories

https://www.rohde-schwarz.com/MNT-5G

https://www.rohde-schwarz.com/MNT/stories

5g mobile network testing

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