LTE Measurement: How to test a device

LTE, UMTS Long Term Evolution LTE measurements – from RF to application testing

Reiner Stuhlfauth

[email protected]

Training Centre

Rohde & Schwarz, Germany

Subject to change – Data without tolerance limits is not binding.

R&S® is a registered trademark of Rohde & Schwarz GmbH & Co. KG. Trade names are trademarks

of the owners.

2011 ROHDE & SCHWARZ GmbH & Co. KG

Test & Measurement Division

- Training Center -

This folder may be taken outside ROHDE & SCHWARZ facilities.

ROHDE & SCHWARZ GmbH reserves the copy right to all of any part of these course notes.

Permission to produce, publish or copy sections or pages of these notes or to translate them must first

be obtained in writing from

ROHDE & SCHWARZ GmbH & Co. KG, Training Center, Mühldorfstr. 15, 81671 Munich, Germany

November 2012 | LTE measurements| 2

Mobile Communications: Fields for testing

l RF testing for mobile stations and user equipment

l RF testing for base stations

l Drive test solutions and verification of network

planning

l Protocol testing, signaling behaviour

l Testing of data end to end applications

l Audio and video quality testing

l Spectrum and EMC testing


Test Architecture RF-/L3-/IP Application-Test


LTE: EPS Bearer

P-GWS-GW Peer

Entity

UE eNB

EPS Bearer

Radio Bearer S1 Bearer

End-to-end Service

External Bearer

Radio S5/S8

Internet

S1

E-UTRAN EPC

Gi

S5/S8 Bearer


Mobile Radio Testing

Core network

A mobile radio tester emulates a

base station

Perform

RF measurements on

received uplink

Generate downlink

signal and send control

commands

Adjust the downlink

signal to how uplink is

received


Mobile Radio Testing

Signaling testing

Generate downlink

signal and send

signaling information

Non-Signaling testing

Control PC

Generate downlink

signal

No signaling


LTE measurements general aspects


LTE RF Testing Aspects UE requirements according to 3GPP TS 36.521 Power

Maximum output power

Maximum power reduction

Additional Maximum Power

Reduction

Minimum output power

Configured Output Power

Power Control

Absolution Power Control

Relative Power Control

Aggregate Power Control

ON/OFF Power time mask

Output RF spectrum emissions

Occupied bandwidth

Out of band emissions

Spectrum emisssion mask

Additional Spectrum emission mask

Adjacent Channel Leakage Ratio

Transmit Intermodulation 36.521: User Equipment (UE) radio

transmission and reception

Transmit signal quality

Frequency error

Modulation quality, EVM

Carrier Leakage

In-Band Emission for non allocated RB

EVM equalizer spectrum flatness


LTE RF Testing Aspects UE requirements according to 3GPP, cont.

Receiver characteristics: Reference sensitivity level

Maximum input level

Adjacent channel selectivity

Blocking characteristics

In-band Blocking

Out of band Blocking

Narrow Band Blocking

Spurious response

Intermodulation characteristics

Spurious emissions

Performance


LTE RF Testing Aspects BS requirements according to 3GPP

l Transmitter Characteristics l Base station output power

l Frequency error

l Output power dynamics

l Transmit ON/OFF power

l Output RF spectrum emissions (Occupied bandwidth, Out of band

emission, BS Spectrum emission mask, ACLR, Spurious emission,

Co-existence scenarios,…)

l Transmit intermodulation

l Modulation quality TR 36.804: Base Station (BS) radio

transmission and reception


LTE RF Testing Aspects BS requirements according to 3GPP, cont.

l Receiver Characteristics l Reference sensitivity level

l Dynamic range

l Adjacent Channel Selectivity (ACS)

l Blocking characteristics

l Intermodulation characteristics

l Spurious emissions

l Performance


LTE RF Measurements – regional requirements

l Regional / band-specific requirements exist (e.g. spurious emissions)

l Since UEs roam implementation has to be dynamic

Concept of network signaled RF requirements has been introduced with

LTE.

- Network signaled value: NS_01 … NS_32

- transmitted as IE AdditionalSpectrumEmission in SIB2


LTE bands and channel bandwidth E-UTRA band / channel bandwidth

E-UTRA Band 1.4 MHz 3 MHz 5 MHz 10 MHz 15 MHz 20 MHz

1 Yes Yes Yes Yes

2 Yes Yes Yes Yes Yes[1] Yes[1]

3 Yes Yes Yes Yes Yes[1] Yes[1]

4 Yes Yes Yes Yes Yes Yes

5 Yes Yes Yes Yes[1]

6 Yes Yes[1]



9 Yes Yes Yes[1] Yes[1]

10 Yes Yes Yes Yes

11 Yes Yes[1]

12 Yes Yes Yes[1] Yes[1]

13 Yes[1] Yes[1]

14 Yes[1] Yes[1]

...

17 Yes[1] Yes[1]

...

33 Yes Yes Yes Yes

34 Yes Yes Yes



37 Yes Yes Yes Yes

38 Yes Yes Yes Yes

39 Yes Yes Yes Yes

40 Yes Yes Yes Yes

NOTE 1: bandwidth for which a relaxation of the specified UE receiver sensitivity requirement (Clause 7.3) is allowed.

Not every channel

bandwidth for

every band!


Tests performed at “low, mid and highest frequency”

lowest EARFCN possible

and 1 RB at position 0

RF p

ow

er

Frequency = whole LTE band

RF p

ow

er

Frequency

RF p

ow

er

Frequency

mid EARFCN

and 1 RB at position 0

Highest EARFCN

and 1 RB at max position

Nominal frequency described by EARFCN (E-UTRA Absolute Radio Frequency Channel Number)


Test Environment – Test System Uncertainty

36.101 / 36.508

• Temperature/Humidity

-normal conditions +15C to +35C, relative humidity 25 % to 75 %

-extreme conditions -10C to +55C (IEC 68-2-1/68-2-2)

• Voltage

• Vibration

Acceptable Test System Uncertainty (Test Tolerance, TT) defined for each test individually

in 36.521 Annex F (will be ignored further on for the sake of simplicity)

Test Minimum Requirement in TS

36.101

Test

Tolerance

(TT)

Test Requirement in TS 36.521-

1

6.2.2. UE

Maximum Output

Power

Power class 1: [FFS]


Power class 3: 23dBm ±2 dB


0.7 dB

0.7 dB

0.7 dB

0.7 dB

Formula:

Upper limit + TT, Lower limit - TT



Power class 3: 23dBm ±2.7 dB



LTE RF measurements on base stations


OFDM risk: Degradation

f

1

MCT

f0 f2

Sa

mp

les

f1 f3 f0 f2 f1 f3

ls n lr n

Channel (ideal)


OFDM risk: Degradation due to Frequency Offset

f

f

f0 f2

Sa

mp

les

f1 f3 f0 f2 f1 f3

2j nfe

ls n lr n

Channel


OFDM risk: Degradation due to Clock Offset

f

f0 f2

Sa

mp

les

f1 f3 f0 f2 f1 f3

ls n lr n

Channel

f k


Subcarrier zero handling

1/TSYMBOL=15kHz

f f-1

f0 f1

Subcarrier 0 or DC subcarrier

causes problems in DAC for

direct receiver strategies, DC offset!

12/

2/

212

,

RBsc

ULRB

RBsc

ULRB

s,CP)(

NN

NNk

TNtfkj

lklleats

2/

1

2)(

,

1

2/

2)(

,

)(

RBsc

DLRB

s,CP)(

RBsc

DLRB

s,CP)(

NN

k

TNtfkjp

lkNNk

TNtfkjp

lk

pl

ll eaeats

Downlink:

Uplink:

DC subcarrier ½ subcarrier

offset

DC subcarrier,

suppressed

f-1 f+1


LTE: DC subcarrier usage

DC subcarrier or subcarrier 0 is not used in downlink!


DC offset – possible reasons

PLL

1st mixer

fLO

fRX=fLO+fBB+fLO_ɛ

fBB=fRx-fLO

Idea: set PLL to frequency fLO to get frequency of baseband

as fBB = fRX – fLO

But: if synthesizer has leakage: fLO_ɛ will spread into the input:

At the output we get direct current, DC!

fLO_ɛ

fLO –fLO_ɛ=DC

Non-linearities of

Amplifier also cause

DC in the signal

fBB + DC

DC offset originated by mixer:


Base station test models Parameter 1.4 MHz 3 MHz 5 MHz 10 MHz 15 MHz 20 MHz

Reference, Synchronisation Signals

RS boosting, PB = EB/EA 1 1 1 1 1 1

Synchronisation signal EPRE / ERS [dB] 0.000 0.000 0.000 0.000 0.000 0.000

Reserved EPRE / ERS [dB] -inf -inf -inf -inf -inf -inf

PBCH

PBCH EPRE / ERS [dB] 0.000 0.000 0.000 0.000 0.000 0.000

Reserved EPRE / ERS [dB] -inf -inf -inf -inf -inf -inf

PCFICH

# of symbols used for control channels 2 1 1 1 1 1

PCFICH EPRE / ERS [dB] 3.222 0 0 0 0 0

PHICH

# of PHICH groups 1 1 1 2 2 3

# of PHICH per group 2 2 2 2 2 2

PHICH BPSK symbol power / ERS [dB] -3.010 -3.010 -3.010 -3.010 -3.010 -3.010

PHICH group EPRE / ERS [dB] 0 0 0 0 0 0

PDCCH

# of available REGs 23 23 43 90 140 187

# of PDCCH 2 2 2 5 7 10

# of CCEs per PDCCH 1 1 2 2 2 2

# of REGs per CCE 9 9 9 9 9 9

# of REGs allocated to PDCCH 18 18 36 90 126 180

# of <NIL> REGs added for padding 5 5 7 0 14 7

PDCCH REG EPRE / ERS [dB] 0.792 2.290 1.880 1.065 1.488 1.195

<NIL> REG EPRE / ERS [dB] -inf -inf -inf -inf -inf -inf

PDSCH

# of QPSK PDSCH PRBs which are boosted 6 15 25 50 75 100

PRB PA = EA/ERS [dB] 0 0 0 0 0 0

# of QPSK PDSCH PRBs which are de-boosted 0 0 0 0 0 0

PRB PA = EA/ERS [dB] n.a. n.a. n.a. n.a. n.a. n.a.

TS 36.141

Defines several

Test models

For base station

e.g. E-TM1.1


Base station unwanted emissions

Spurious domain

RB

Channel bandwidth Spurious domain

ΔfOOB

ΔfOOB

E-UTRA Band

Worst case:

Ressource Blocks allocated

at channel edge

ACLR Spurious emissions

•Adjacent channel leakage

•Operating band unwanted emissions


Adjacent Channel Leakage Ratio - eNB

E-UTRA transmitted

signal channel

bandwidth

BWChannel [MHz]

BS adjacent channel

centre

frequency offset

below the first

or above the last

carrier centre

frequency

transmitted

Assumed

adjacent

channel

carrier

(informative)

Filter on the

adjacent

channel

frequency and

corresponding

filter bandwidth

ACLR

lim

it

1.4, 3.0, 5, 10, 15, 20 BWChannel E-UTRA of same

BW

Square (BWConfig) 45 dB

2 x BWChannel E-UTRA of same

BW

Square (BWConfig) 45 dB

BWChannel /2 + 2.5

MHz

3.84 Mcps UTRA RRC (3.84 Mcps) 45 dB

BWChannel /2 + 7.5

MHz

3.84 Mcps UTRA RRC (3.84 Mcps) 45 dB

NOTE 1: BWChannel and BWConfig are the channel bandwidth and transmission bandwidth configuration

of the E-UTRA transmitted signal on the assigned channel frequency.

NOTE 2: The RRC filter shall be equivalent to the transmit pulse shape filter defined in TS 25.104 [6],

with a chip rate as defined in this table. Limit is either -13 / -15dBm absolute or as above

Large bandwidth


Adjacent channel leakage power ratio


A

Ref 0 dBm Att 25 dB

EXT

1 AP

VIEW

Center 1.947 GHz Span 25 MHz2.5 MHz/

2 AP

VIEW

CLRWR

*

3DB

RBW 10 kHz

SWT 250 ms

VBW 30 kHz

3 AP

*

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

Date: 21.AUG.2008 15:51:00

ACLR measurement

fCarrier fUTRA, ACLR2 fUTRA, ACLR1

UTRAACLR1

= 33 dB

UTRAACLR2

= 36 dB UTRAACLR2bis

= 43 dB

Additional requirement for

E-UTRA frequency band I,

signaled by network to the UE


Operating band unwanted emissions

dBMHz

offsetfdBm

05.0

_

5

77

Frequency offset

of measurement

filter -3dB point, f

Frequency offset of

measurement filter centre

frequency, f_offset

Minimum requirement Measurem

ent

bandwidth

(Note 1)

0 MHz f < 5

MHz

0.05 MHz f_offset < 5.05

MHz

100 kHz

5 MHz f <

min(10 MHz,

fmax)

5.05 MHz f_offset <

min(10.05 MHz,

f_offsetmax)

-14 dBm 100 kHz

10 MHz f

fmax

10.05 MHz f_offset <

f_offsetmax

-16 dBm (Note 5) 100 kHz

TS 36.104 defines several limits: depending on

Channel bandwidth, additional regional limits and node B

limits category A or B for ITU defined regions

=> Several test setups are possible!

Narrow bandwidth


Operating band unwanted emissions


Unwanted emissions – spurious emission

The transmitter spurious emission limits apply from 9 kHz to 12.75 GHz,

excluding the frequency range from 10 MHz below the lowest frequency of the downlink

operating band up to 10 MHz above the highest frequency of the downlink operating band

Frequency range Maximum level Measurement

Bandwidth

Note

9kHz - 150kHz

-13 dBm

1 kHz Note 1

150kHz - 30MHz 10 kHz Note 1

30MHz - 1GHz 100 kHz Note 1

1GHz – 12.75 GHz 1 MHz Note 2

NOTE 1: Bandwidth as in ITU-R SM.329 [5] , s4.1

NOTE 2: Bandwidth as in ITU-R SM.329 [5] , s4.1. Upper frequency as in ITU-R SM.329 [5] , s2.5 table 1

Spurious emission limits, Category A


Spurious emissions – operating band excluded


Base station maximum power

BS

cabinet

Test port A Test port B

External

device

e.g.

TX filter

(if any)

External

PA

(if any)

Towards

antenna connector

Normal port for

measurements Port to be used for

measurements in case

external equipment is

used

In normal conditions, the base station maximum output power

shall remain within +2 dB and -2 dB of the rated output power

declared by the manufacturer.


LTE – DVB interference scenarios

For a BS declared to support Band 20 and to operate in geographic areas within the CEPT in which frequencies are allocated to broadcasting (DTT) service, the manufacturer shall additionally declare the following quantities associated with the applicable test conditions of Table 6.6.3.5.3-4 and information in annex G of [TS 36.104] :

PEM,N Declared emission level for channel N P10MHz Maximum output Power in 10 MHz

Adjacent channel leakage of

Basestation x into DTT channel N

is point of interest


Base station receiver test

70% of required throughput of FRC, Fixed Reference Channel

Example: Rx test, moving condition


Base station receiver test – HARQ multiplexing

UE sends PUSCH with alternating data

and data with multiplexed ACK


Base station test – power dynamics

BS under

Test

RF-

correc-

tion

FFT

2048 Per

subcarrier

Ampl.

/Phase

correction

Symbol

Detection /

decoding

100

RBs,

1200

sub

carr

CP-

remov

EVM

RETP

Synchronisation

time/frequency

Resource element Tx

power: Distinguish:

•OFDM symbol

•Reference symbol


[Time]

Downlink Power

[Power]

0 1 2 3 4 5 6 7 8 9 10 11 12 13

OFDM symbols

-50.00 dBm

PA = -4.77 dB

-54.77 dBm

-58.75 dBm

PB = 3 (-3.98 dB)

PDSCH power to RS, where NO reference

signals are present, is UE specific and

signaled by higher layers as PA.

Reference Signal:

Cell-specific

referenceSignalPower

(-60…+50dBm),

signaled in SIB Type 2 For PDSCH power in same

symbol as reference signal an

additional cell specific offset

is applied, that is signaled by

higher layers as PB.

PDCCH power

depending

on ρB/ρA

2011 ©

Ro

hd

e&

Sch

warz

RSBAPDSCH EPREEPRE /B B AP MIMO)for exeptions some(with AA P

RS EPRE = Reference Signal

Energy per Resource Element

Reference signal power = linear average of all Ref.

Symbols over whole channel bandwidth


Base station test – output power dynamics

Ref. Symbol, always on

OFDM Symbol not active!

OFDM Symbol active!

Measure avg OFDM

symbol power +

Compare active and

non-active case

PDSCH

# of 64QAM PDSCH PRBs within a slot for which EVM is measured

1 1 1 1 1 1

PRB PA = EA/ERS [dB] 0 0 0 0 0 0

# of PDSCH PRBs which are not allocated 5 14 24 49 74 99

PDSCH

# of 64QAM PDSCH PRBs within a slot for which EVM is measured

6 15 25 50 75 100

Test model:

E-TM3.1

All RB allocated

Test model:

E-TM2

Only 1 RB allocated


DL Modulation quality: Constellation diagram LTE downlink: several channels can be seen (example):

PDSCH with

16 QAM

PDCCH +

PBCH with

QPSK

S-SCH with

BPSK

CAZAC

Sequences,

Reference signals


LTE RF measurements on user equipment UEs


LTE Transmitter Measurements 1 Transmit power

1.1 UE Maximum Output Power

1.2 Maximum Power Reduction (MPR)

1.3 Additional Maximum Power Reduction (A-MPR)

1.4 Configured UE transmitted Output Power

2 Output Power Dynamics

2.1 Minimum Output Power

2.2 Transmit OFF power

2.3 ON/OFF time mask

2.3.1 General ON/OFF time mask

2.3.2 PRACH time mask

2.3.3 SRS time mask

2.4 Power Control

2.4.1 Power Control Absolute power tolerance

2.4.2 Power Control Relative power tolerance

2.4.3 Aggregate power control tolerance

3 Transmit signal quality

3.1 Frequency Error

3.2 Transmit modulation

3.2.1 Error Vector Magnitude (EVM)

3.2.2 Carrier leakage

3.2.3 In-band emissions for non allocated RB

3.2.4 EVM equalizer spectrum flatness

4 Output RF spectrum emissions

4.1 Occupied bandwidth

4.2 Out of band emission

4.2.1 Spectrum Emission Mask

4.2.2 Additional Spectrum Emission Mask

4.2.3 Adjacent Channel Leakage power Ratio

4.3 Spurious emissions

4.3.1 Transmitter Spurious emissions

4.3.2 Spurious emission band UE co-existence

4.3.3 Additional spurious emissions

5 Transmit intermodulation


UE Signal quality – symbolic structure of mobile radio tester MRT

RF correction FFT

TxRx

equalizer EVM meas. IDFT

Test equipment

Rx

…

…

…

…

…

…

Inband-

emmissions

l Carrier Frequency error

l EVM (Error Vector Magnitude)

l Origin offset + IQ offset

l Unwanted emissions, falling into non allocated resource blocks.

l Inband transmission

l Spectrum flatness

DUT


UL Power Control: Overview

UL-Power Control is a

combination of:

l Open-loop:

UE estimates the DL-Path-

loss and compensates it

for the UL

l Closed-loop:

in addition, the eNB

controls directly the UL-

Power through power-

control commands

transmitted on the DL


PUSCH power control

l Power level [dBm] of PUSCH is calculated every subframe i based on the following

formula out of TS 36.213

Dynamic offset (closed loop) Basic open-loop starting point

Maximum allowed UE power

in this particular cell,

but at maximum +23 dBm1)

Number of allocated

resource blocks (RB)

Combination of cell- and UE-specific

components configured by L3

Cell-specific

parameter

configured by L3

PUSCH transport

format

Transmit power for PUSCH

in subframe i in dBm

Power control

adjustment derived

from TPC command

received in subframe (i-4)

Downlink

path loss

estimate

Bandwidth factor

1) +23 dBm is maximum allowed power in LTE according to TS 36.101, corresponding to power class 3bis in WCDMA

MPR


„upper“ tolerance Pcmax definition

PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H)

„corrected“ UE power

PCMAX_L = min{PEMAX_L, PUMAX } PCMAX_H = min{PEMAX_H, PPowerClass}

„lower“ tolerance

Max. power permitted

in cell,

considering bandwidth

confinement

Max. power for UE,

considering maximum

power reduction

Max. power

permitted in cell

Max. power for

UE


PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H),

l PEMAX_L is the maximum allowed power for this particular radio cell

configured by higher layers and corresponds to P-MAX information

element (IE) provided in SIB Type1

l

l PEMAX_L is reduced by 1.5 dB when the transmission BW is confined within

FUL_low and FUL_low+4 MHz or FUL_high – 4 MHz and FUL_high,

Pcmax definition

lPCMAX_L = min{PEMAX_L , PUMAX },

FUL_low FUL_high

PPowerClass +

2dB

PPowerClass - 2dB 23dBm

FUL_high- 4MHz

-1.5dB -1.5dB


PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H),

l PUMAX corresponds to maximum power (depending on power class,

taking into account Maximum Power Reduction MPR and additional

A-MPR

Pcmax definition

PCMAX_L = min{PEMAX_L , PUMAX },

UE power class

= 23dBm ±2 dB Network may signal

bandwidth restriction

NS_0x

UE may decide to

reduce power


UE Maximum Power Reduction

UE transmits

at maximum power, maximum allowed

TX power reduction is given as

Modulation Channel bandwidth / Transmission bandwidth configuration

[RB]

MPR (dB)

1.4

MHz

3.0

MHz

5

MHz

10

MHz

15

MHz

20

MHz

QPSK > 5 > 4 > 8 > 12 > 16 > 18 ≤ 1

16 QAM ≤ 5 ≤ 4 ≤ 8 ≤ 12 ≤ 16 ≤ 18 ≤ 1

16 QAM Full > 5 > 4 > 8 > 12 > 16 > 18 ≤ 2

Higher order modulation schemes require

more dynamic -> UE will slightly repeal its

confinement for maximum power


UE Additional Maximum Power Reduction A-MPR

Network

Signaling

value

Requirements

(sub-clause)

E-UTRA Band Channel

Bandwidth

(MHz)

Resource

Blocks

A-MPR (dB)

NS_01 NA NA NA NA NA

NS_03

6.6.2.2.3.1 2,4,35,36 3 >5 ≤ 1

6.6.2.2.3.1 2,4,10,35,36 5 >6 ≤ 1

6.6.2.2.3.1 2,4,10,35,36 10 >6 ≤ 1

6.6.2.2.3.1 2,4,10,35,36 15 >8 ≤ 1

6.6.2.2.3.1 2,4,10,35,36 20 >10 ≤ 1

NS_04 6.6.2.2.3.2 TBD TBD TBD TBD

NS_05 6.6.3.3.3.1 1 10,15,20 ≥ 50 for QPSK ≤ 1

NS_06 6.6.2.2.3.3 12, 13, 14, 17 1.4, 3, 5, 10 n/a n/a

NS_07 6.6.2.2.3.3

6.6.3.3.3.2 13 10 Table 6.2.4.3-2

Table

6.2.4.3-2

NS_08 6.6.3.3.3.3 19 10, 15

> 29 ≤ 1

> 39 ≤ 2

> 44 ≤ 3

[NS_09] 6.6.3.3.3.4 21 TBD TBD TBD

..

NS_32 - - - - -

Additional maximum

power reduction

requirements can be

signaled by the

network as NS value

in SIB2 (IE AdditionalSpectrumEmission)


PUSCH power control Transmit output power ( PUMAX), cont’d.

l In case of EUTRA Band 13 depending on RB allocation as well as

number of contiguously allocated RB different A-MPR needs to be

considered.

Network

Signalling

Value

Requiremen

ts

(sub-clause)

E-UTRA

Band

Channel

bandwidth

(MHz)

Resources

Blocks

A-MPR

(dB)

… … … … … …

NS_07 6.6.2.2.3

6.6.3.3.2 13 10

Table

6.2.4

-2

Table

6.2.4

-2

… … … … … …

Region A Region B Region C

RBStart 0 – 12 13 – 18 19 – 42 43 – 49

LCRB [RBs] 6 – 8 1 – 5 to 9 – 50 ≥8 ≥18 ≤2

A-MPR [dB] 8 12 12 6 3

Indicates the lowest RB

index of transmitted

resource blocks

Defines the length of a

contiguous RB allocation

DL UL

756 746 787 777

3GPP Band 13



Pcmax definition – tolerance values

PCMAx

(dBm)

Tolerance

T(PCMAX) (dB)

21 ≤ PCMAX ≤ 23 2.0

20 ≤ PCMAX < 21 2.5

19 ≤ PCMAX < 20 3.5

18 ≤ PCMAX < 19 4.0

13 ≤ PCMAX < 18 5.0

8 ≤ PCMAX < 13 6.0

-40 ≤ PCMAX < 8 7.0

Tolerance is

depending on

power levels



l PEMAX_H is the maximum allowed power for this particular radio

cell configured by higher layers and corresponds to P-MAX

information element (IE) provided in SIB Type 1


PCMAX_H = min{PEMAX_H , PPowerClass },

UE power class

= 23dBm ±2 dB



l PPowerClass. There is just one power class specified for LTE,

corresponding to power class 3bis in WCDMA with +23 dBm ± 2dB,

MPR and A-MPR are not taken into account,


PCMAX_H = min{PEMAX_H , PPowerClass },

EUTRA

band

Class 1

(dB

m)

Tolerance

(dB)

Class 2

(dBm)

Tolerance

(dB)

Class 3

(dBm

)

Tolerance (dB) Class 4

(dBm)

Tolerance (dB)

1 23 ±2

2 23 ±22

… 23 ±22

40 23 ±2


Pcmax value for power control - analogies

Maximum speed = 280 km/h

=PPowerClass

=PEMAX_H =PEMAX_L =PUMAX

Under those conditions,

I shall drive more carefully!

Not going to the max seed!

-> speed reduction




LTE RF Testing: UE Maximum Power

UE transmits

with 23dBm ±2 dB

QPSK modulation is used. All channel bandwidths are

tested separately. Max power is for all band classes

Test is performed for varios uplink allocations


Resource Blocks number and maximum RF power

One active resource block

(RB) provides maximum

absolute RF power RF p

ow

er

Frequency

RF p

ow

er

Frequency

More RB’s in use will be at

lower RF power in order to

create same integrated

power

1 active resource block (RB),

Nominal band width 10 MHz = 50 RB’s

RF p

ow

er

Frequency

Additionally, MPR (Max.

Power Reduction) and A-

MPR are defined MPR


UE Maximum Output Power – Test Configuration Initial Conditions

Test Environment as specified in TS 36.508 subclause 4.1 Normal, TL/VL, TL/VH, TH/VL, TH/VH

Test Frequencies as specified in TS 36.508 subclause 4.3.1 Low range, Mid range, High range

Test Channel Bandwidths as specified in TS 36.508 subclause 4.3.1 Lowest, 5MHz, Highest

Test Parameters for Channel Bandwidths

Downlink Configuration Uplink Configuration

Ch BW N/A for Max UE output power testing Mod’n RB allocation

FDD TDD

1.4MHz QPSK 1 1

1.4MHz QPSK 5 5

3MHz QPSK 1 1

3MHz QPSK 4 4

5MHz QPSK 1 1

5MHz QPSK 8 8

10MHz QPSK 1 1

10MHz QPSK 12 12

15MHz QPSK 1 1

15MHz QPSK 16 16

20MHz QPSK 1 1

20MHz QPSK 18 18

Temperature/Voltage

high/low


UE maximum power

FUL_low FUL_high

PPowerClass + 2dB

PPowerClass - 2dB

maximum output

power for any

transmission bandwidth

within the channel bandwidth

23dBm


UE maximum power – careful at band edge!

FUL_low FUL_high

PPowerClass + 2dB

PPowerClass - 2dB

23dBm

FUL_high- 4MHz FUL_low+4MHz

For transmission bandwidths confined within FUL_low and FUL_low + 4 MHz or

FUL_high – 4 MHz and FUL_high, the maximum output power requirement is relaxed

by reducing the lower tolerance limit by 1.5 dB

-1.5dB -1.5dB


UE maximum power - examples

FUL_low FUL_high

PPowerClass + 2dB

PPowerClass - 2dB

23dBm

Example 1: No maximum power reduction by higher layers



Max. power permitted in cell,

considering bandwidth

confinement

Max. power for UE,

considering maximum power

reduction

Max. power permitted in

cell Max. power for UE

PEMAX_L = none PUMAX = power class 3 = +23 dBm

PEMAX_H = none PPowerClass = power class 3 = +23 dBm 25dBm

21dBm

T(PCMAX_L) = T(PCMAX_H)=2dB



FUL_low FUL_high

PCMAX_H + 7dB

PCMAX_L - 7dB

0 dBm

Example 2: max cell power = 0 dBm + band edge maximum power reduction



PEMAX_L = 0dBm -1.5 dB relaxation = -1.5dBm

PUMAX = power class 3 – band relaxation = +21.5 dBm

+7dBm

-8.5dBm

T(PCMAX_L) = T(PCMAX_H)=7dB

PEMAX_H = 0 dBm

PPowerClass = power class 3 = +23 dBm

PCMAX_L=-1.5dBm PCMAX_H=0 dBm

FUL_low+4MHz



RB start = 13 FUL_high

PCMAX_H +2dB

PCMAX_L - 6dB

23 dBm

Example 3: Band 13 with NS_07 signalled ( = A-MPR). No Max Power restriction

16 QAM, 12 Resource blocks and RB start = 13. Bandwidth = 10 MHz



PEMAX_L = none

PUMAX = power class 3 – MPR – A.MPR = +10 dBm

+25dBm

4 dBm

T(PCMAX_L) = 6 dB

T(PCMAX_H)=2dB

PEMAX_H = none


PCMAX_L=10 dBm PCMAX_H=23 dBm

12 Resource blocks

MPR = 1dB, A-MPR = 12 dB, no band edge relaxation



FUL_low FUL_high

PCMAX_H + 2dB

PCMAX_L – 2 dB

23 dBm

Example 4: band edge power relaxation – no higher layer reduction signalled

QPSK, 15 RBs allocated, Band 2, RB allocated at band edge



PEMAX_L =none

PUMAX = power class 3 – MPR-A-MPR-band relaxation

= 23-1-1-1.5=+19.5 dBm

+25 dBm

+16 dBm

PEMAX_H = none


PCMAX_L=19.5dBm

PCMAX_H= 23 dBm

FUL_low+4MHz

MPR = 1dB, A-MPR = 1 dB, band edge relaxation of 1.5dB

T(PCMAX_L) = 3.5 dB

T(PCMAX_H)=2dB

PCMAX_L – 3.5 dB


LTE RF Testing: UE Minimum Power

UE transmits

with -40dBm

All channel bandwidths are tested separately.

Minimum power is for all band classes < -39 dBm


LTE RF Testing: UE Off Power

The transmit OFF power is defined as the mean power in a duration of at least one

sub-frame (1ms) excluding any transient periods. The transmit OFF power shall not

exceed the values specified in table below

Channel bandwidth / Minimum output power / measurement bandwidth

1.4

MHz

3.0

MHz

5

MHz

10

MHz

15

MHz

20

MHz

Transmit OFF power -50 dBm

Measurement

bandwidth 1.08 MHz 2.7 MHz 4.5 MHz 9.0 MHz 13.5 MHz 18 MHz


Power Control Related test items

l Absolute Power Control Tolerance -- PUSCH open loop

power control

l Relative Power Control Tolerance – PUSCH relative power

control, including both power ramping and power change due

to Ressource block allocation change or TPC commands

l Aggregate Power Control – PUSCH and PUCCH power

control ability when RB changes every subframe


Absolute Power Control Tolerance

l The purpose of this test is to verify the UE transmitter’s

ability to set its initial output power to a specific value at the

start of a contiguous transmission or non-contiguous

transmission with a long transmission gap.


Power Control - Absolute Power Tolerance

l …. ability to set initial output power to a specific value at the start of a

contiguous transmission or non-contiguous transmission with a long

transmission gap (>20ms).

l Set p0-NominalPUSCH to -105 (test point 1) and -93 (test point 2)

l Test requirement example for test point 1:

Channel bandwidth / expected output power (dBm)

1.4

MHz

3.0

MHz

5

MHz

10

MHz

15

MHz

20

MHz

Expected Measured

power Normal

conditions

-14.8 ±

10.0

-10.8 ±

10.0

-8.6 ±

10.0

-5.6 ±

10.0

-3.9 ±

10.0

-2.6 ±

10.0

Expected Measured

power Extreme

conditions

-14.8 ±

13.0

-10.8 ±

13.0

-8.6 ±

13.0

-5.6 ±

13.0

-3.9 ±

13.0

-2.6 ±

13.0


Configured UE transmitted Output Power

Test: set P-Max to -10, 10 and 15 dBm, measure PCMAX

IE P-Max (SIB1) = PEMAX

Channel bandwidth / maximum output power

1.4

MHz

3.0

MHz

5

MHz

10

MHz

15

MHz

20

MHz

PCMAX test point 1 -10 dBm ± 7.7

PCMAX test point 2 10 dBm ± 6.7

PCMAX test point 3 15 dBm ± 5.7

To verify that UE follows rules sent via

system information, SIB


LTE Power versus time

)}())(()())((log10,min{)( TFO_PUSCHPUSCH10MAXPUSCH ifiTFPLjPiMPiP

Bandwidth allocation TPC commands Given by higher layers

or not used

RB allocation

is main source for

power change

Not scheduled

Resource block


2

Accumulative TPC commands

TPC Command Field

In DCI format 0/3

Accumulated

[dB]

0 -1

1 0

2 1

3 3

PUSCH

minimum

power in LTE


Absolute TPC commands

TPC Command Field

In DCI format 0/3

Absolute [dB]

only DCI format 0

0 -4

1 -1

2 1

3 4

PUSCH

Pm

)}())(()())((log10,min{)( TFO_PUSCHPUSCH10MAXPUSCH ifiTFPLjPiMPiP

-4 -1


Relative Power Control

0 .. 9 sub-frame# 1 2 3 4 radio frame


RB change

RB change

Power pattern A

Power pattern C


RB change

Power pattern B

l The purpose of this test is to verify

the ability of the UE transmitter to set

its output power relatively to the

power in a target sub-frame, relatively

to the power of the most recently

transmitted reference sub-frame, if the

transmission gap between these sub-

frames is ≤ 20 ms.


Power Control – Relative Power Tolerance

l …. ability to set output power relative to the power in a target sub

frame, relative to the power of the most recently transmitted

reference sub-frame, if the transmission gap between these

sub-frames is ≤ 20 ms.


Power Control – Relative Power Tolerance

l Various power ramping patterns are defined

ramping up

ramping down

alternating


UE power measurements – relative power change

Power step P

(Up or down)

[dB]

All combinations of

PUSCH and

PUCCH

transitions [dB]

All combinations of

PUSCH/PUCCH

and SRS

transitions

between sub-

frames [dB]

PRACH [dB]

ΔP < 2 ±2.5 (Note 3) ±3.0 ±2.5

2 ≤ ΔP < 3 ±3.0 ±4.0 ±3.0

3 ≤ ΔP < 4 ±3.5 ±5.0 ±3.5

4 ≤ ΔP ≤ 10 ±4.0 ±6.0 ±4.0

10 ≤ ΔP < 15 ±5.0 ±8.0 ±5.0

15 ≤ ΔP ±6.0 ±9.0 ±6.0

P

time

Power tolerance relative given by table


UE power measurements – relative power change

Power

FDD test patterns

0 1 9 sub-frame#

Power

TDD test patterns

0 2 3 7 8 9 sub-frame#

Sub-test Uplink RB allocation TPC command Expected power

step size

(Up or

down)

Power step size

range (Up or

down)

PUSCH/

ΔP [dB] ΔP [dB] [dB]

A Fixed = 25 Alternating TPC =

+/-1dB 1 ΔP < 2 1 ± (1.7)

B Alternating 10 and 18 TPC=0dB 2.55 2 ≤ ΔP < 3 2.55 ± (3.7)

C Alternating 10 and 24 TPC=0dB 3.80 3 ≤ ΔP < 4 3.80 ± (42.)

D Alternating 2 and 8 TPC=0dB 6.02 4 ≤ ΔP < 10 6.02 ± (4.7)

E Alternating 1 and 25 TPC=0dB 13.98 10 ≤ ΔP < 15 13.98 ± (5.7)

F Alternating 1 and 50 TPC=0dB 16.99 15 ≤ ΔP 16.99 ± (6.7)

test for

each

bandwidth,

here 10MHz


UE aggregate power tolerance

Aggregate power control tolerance is the ability of a UE to maintain its power in

non-contiguous transmission within 21 ms in response to 0 dB TPC commands

TPC command UL channel Aggregate power tolerance within 21 ms

0 dB PUCCH ±2.5 dB

0 dB PUSCH ±3.5 dB

Note:

1. The UE transmission gap is 4 ms. TPC command is transmitted via PDCCH 4 subframes preceding

each PUCCH/PUSCH transmission.

P

Time = 21 milliseconds

UE power with

TPC = 0

Tolerated UE power

deviation


Aggregate Power Control

l The purpose of this test is to verify the UE’s ability to

maintain its power level during a non-contiguous

transmission within 21 ms in response to 0 dB TPC

commands with respect to the first UE transmission, when

the power control parameters specified in TS 36.213 are

constant.

l Both PUSCH mode and PUCCH mode need to be tested

Power

FDD test patterns

0 5 0 5 0

sub-frame#

Power

TDD test patterns

3 8 3 8 3

sub-frame#


UE aggregate power tolerance

Power

FDD test patterns

0 5 0 5 0

sub-frame#

Power

TDD test patterns

3 8 3 8 3

sub-frame#

Test performed with scheduling gap of 4 subframes


UE power measurement – timing masks

End of OFF power

20µs 20µs

Transient period Transient period

Start of OFF power

Start of ON power

requirement

Start Sub-frame End sub-frame

End of ON power

requirement

* The OFF power requirements does not

apply for DTX and measurement gaps

Timing definition OFF – ON commands

Timing definition ON – OFF commands


Power dynamics

PUSCH = ON PUSCH = OFF PUSCH = OFF time

Please note: scheduling cadence for power dynamics


General ON/OFF time mask Measured subframe = 2

UL/DL Scheduling should be configured properly.

TDD Issues: - Special Subframe

Configuration

- >off power before is

highter than off

power after

- <> tune down DL

power


PRACH time mask

ON power requirement

requirement

20µs 20µs


PRACH

End of OFF power Start of OFF power

requirement

PRACH

preamble

format

Measurement

period (ms)

0 0.9031

1 1.4844

2 1.8031

3 2.2844

4 0.1479

Channel bandwidth / Output Power [dBm] / measurement

bandwidth

1.4

MHz

3.0

MHz

5

MHz

10

MHz

15

MHz

20

MHz

Transmit OFF

power -48.5 dBm

Transmission OFF

Measurement

bandwidth

1.08 MHz 2.7 MHz 4.5 MHz 9.0 MHz 13.5 MHz 18 MHz

Expected PRACH

Transmission ON

Measured power

-1± 7.5 -1 ± 7.5 -1 ± 7.5 -1 ± 7.5 -1 ± 7.5 -1 ± 7.5


UE power measurement – PRACH timing mask

ON power requirement

requirement

20µs 20µs


PRACH

End of OFF power Start of OFF power

requirement

PRACH preamble format Measurement period (ms)

0 0.9031

1 1.4844

2 1.8031

3 2.2844

4 0.1479


PRACH measurements

For PRACH

you have to

set a trigger Reminder:

PRACH is

CAZAC

sequence


PRACH measurement: constellation diagram

Reminder:

PRACH is

CAZAC

sequence


PRACH measurement: power dynamics


Sounding Reference Signal Time Mask


UE power measurement – SRS timing mask

requirement

20µs 20µs


End of OFF

power requirement

SRS

SRS ON power

requirement

Start of OFF power

End of OFF

20µs 20µs 20µs 20µs

* Transient period is only specifed in the case of frequency hopping or a power change between SRS symbols

*Transient periodTransient period

SRS SRS

requirement

Transient period

Start of OFF power

power requirement

SRS ON power

requirement

SRS ON power

requirement

Single Sounding

Reference Symbol

Double Sounding

Reference Symbol


UE power measurement – Subframe / slot boundary

20µs 20µs 20µs 20µs 20µs 20µs

Transient period Transient period Transient period

Start of N+1 power

requirement

End of N+1 power

requirement

N+1 Sub-frame

Sloti Sloti+1

N0 Sub-frame N+2 Sub-frame

Periods where power changes may occur

If intra-slot hopping is enabled


Tx power aspects RB power = Ressource Block Power, power of 1 RB TX power = integrated power of all assigned RBs


Resource allocation versus time

PUSCH allocation, different #RB and RB offset

PUCCH

allocation

No resource

scheduled


TTI based scheduling


LTE scheduling impact on power versus time

TTI based scheduling.

Different RB allocation

Impact

on UE

power


Transmit signal quality


Transmit signal quality – carrier leakage

f

Parameters Relative Limit (dBc)

Output power >0 dBm -25

-30 dBm ≤ Output power ≤0 dBm -20

-40 dBm Output power < -30 dBm -10

Carrier leakage (The IQ origin offset) is an additive sinusoid waveform

that has the same frequency as the modulated waveform carrier frequency.

Frequency error

fc Fc+ε


Frequency Error

…. ability of both the receiver and the transmitter to process frequencies

correctly…

The 20 frequency error Δf results must fulfil this test requirement:

|Δf| ≤ (0.1 PPM + 15 Hz)

observed over a period of one time slot (0.5ms)


Impact on Tx modulation accuracy evaluation

l 3 modulation accuracy requirements

l EVM for the allocated RBs

l LO leakage for the centred RBs ! LO spread on all RBs

l I/Q imbalance in the image RBs

frequency

RF carrier

RB0 RB1 RB2 RB3 RB4 RB5

level

signal

noise

LO leakage

I/Q imbalance

EVM


Inband emissions

Used

allocation <

½ channel

bandwidth

channel bandwidth

3 types of inband emissions: general, DC and IQ image


Carrier Leakage Carrier leakage (the I/Q origin offset) is a form of interference caused by crosstalk or DC offset.

It expresses itself as an un-modulated sine wave with the carrier frequency.

I/Q origin offset interferes with the center sub carriers of the UE under test.

The purpose of this test is to evaluate the UE transmitter to verify its modulation quality in

terms of carrier leakage.

DC carrier leakage

due to IQ offset

LO

Leakage

Parameters Relative

Limit (dBc)

Output power >0 dBm -25

-30 dBm ≤ Output power ≤0 dBm -20

-40 dBm Output power < -30 dBm -10


Inband emmission – error cases DC carrier leakage

due to IQ offset


Inband emmission – error cases Inband image

due to IQ inbalance


DC leakage and IQ imbalance in real world …


UL Modulation quality: Constellation diagram LTE PUSCH uses

QPSK, 16QAM

and 64 QAM (optional)

modulation schemes.

In UL there is only 1 scheme

allowed per subframe


Error Vector Magnitude, EVM

Error Vector

Q

I

Ideal (Reference) Signal

Measured

Signal

Φ

Phase Error (IQ error phase)

Magnitude Error (IQ error magnitude)

Σ

Demodulator Ideal

Modulator Input Signal

-

+

011001…

Reference Waveform

Measured Waveform

Difference Signal


Error Vector Magnitude, EVM 7 symbols / slot

0 1 2 3 4 5 6 0 1 2 3 4 5 6 0 1 2 3 4 5 6 0 1 2 3 4 5 6 time

frequency

PUSCH symbol

Demodulation Reference

symbol, DMRS

Parameter

Unit Level

QPSK % 17.5

16QAM % 12.5

64QAM % [tbd]

Limit values



Cyclic

prefix

OFDM

Symbol

Part equal

to CP

1 SC-FDMA symbol, including Cyclic Prefix, CP CP center

FFT Window size

FFT window size depends

on channel bandwidth and

extended/normal CP length



Cyclic

prefix

OFDM

Symbol

Part equal

to CP

1 SC-FDMA symbol, including Cyclic Prefix, CP CP center

FFT Window size

cpN

Cyclic prefix length

cpNChannel

Bandwidt

h MHz

for symbol 0 for symbols 1

to 6

Nominal

FFT size

Cyclic prefix

for symbols

1 to 6 in FFT

samples

EVM

window

length

W

Ratio of

W to CP

for

symbols 1

to 6*

1.4

160 144

128 9 [5] [55.6]

3 256 18 [12] [66.7]

5 512 36 [32] [88.9]

10 1024 72 [66] [91.7]

15 1536 108 [102] [94.4]

20 2048 144 [136] [94.4]

* Note: These percentages are informative and apply to symbols 1 through 6. Symbol 0 has a

longer CP and therefore a lower percentage.

FFT window size depends on channel bandwidth

and extended/normal CP length

Table from TS 36.101 for normal CP

FFT window does

not capture the

full length: OFDM

Symbol + CP


EVM measurement according to Spec

l Applies to PUSCH, PUCCH

and PRACH

l PUSCH and PUCCH UL Tx

Pwer

l @ Max & -36.8 dBm

l PRACH UL Tx Power

l FDD: @ -31 dBm & 14 dBm*

l TDD: @ -39 dBm & 6 dBm

Test Parameters for Channel Bandwidths

Downlink

Configuration

Uplink Configuration

Ch BW N/A for PUSCH EVM

testing

Mod’n RB allocation

FDD TDD

1.4MHz QPSK 6 6

1.4MHz QPSK 1 1

1.4MHz 16QAM 6 6

1.4MHz 16QAM 1 1

3MHz QPSK 15 15

3MHz QPSK 4 4

3MHz 16QAM 15 15

3MHz 16QAM 4 4

5MHz QPSK 25 25

5MHz QPSK 8 8

5MHz 16QAM 25 25

5MHz 16QAM 8 8

10MHz QPSK 50 50

10MHz QPSK 12 12

10MHz 16QAM 50

(Note 3)

50

(Note 3)

10MHz 16QAM 12 12

15MHz QPSK 75 75

15MHz QPSK 16 16

15MHz 16QAM 75

(Note 3)

75

(Note 3)

15MHz 16QAM 16 16

20MHz QPSK 100 100

20MHz QPSK 18 18

20MHz 16QAM 100

(Note 3)

100

(Note 3)

20MHz 16QAM 18 18

Note 1: Test Channel Bandwidths are checked separately for each E-

UTRA band, which applicable channel bandwidths are specified in Table

5.4.2.1-1.

Note 2: For partial RB allocation, the starting resource block shall be

RB #0 and RB# (max+1 - RB allocation) of the channel bandwidth.

Note 3: Applies only for UE-Categories 2-5

* 20MHz, we can only reach 13 dBm


Cyclic prefix aspects

OFDM symbol is periodic!

Cyclic prefix does not provoque

phase shift

OFDM symbol n OFDM symbol n-1

We can observe a phase shift

Content is

different in each

OFDM symbol

CP CP

part CP

CP

part


Time windowing

Cyclic

prefix

OFDM

Symbol

Part equal

to CP

1 SC-FDMA symbol, including Cyclic Prefix, CP

Cyclic

prefix

OFDM

Symbol

Part equal

to CP

1 SC-FDMA symbol, including Cyclic Prefix, CP

Continuous phase shift

Difference in phase shift

Phase shift between SC-FDMA

symbols will cause side lobes

in spectrum display!


Time windowing

Cyclic

prefix

OFDM

Symbol

Part equal

to CP

Cyclic

prefix

OFDM

Symbol

Part equal

to CP

Continuous phase shift Difference in phase shift

Tx Time window Tx Time window

Tx time window creates

some kind of clipping in

symbol transitions

Tx time window can be used

to shape the Tx spectrum in

a more steep way, but ….


Time windowing

Cyclic

prefix

OFDM

Symbol

Part equal

to CP

Cyclic

prefix

OFDM

Symbol

Part equal

to CP

Continuous phase shift Difference in phase shift

Tx Time window Tx Time window

Tx time window creates

some kind of clipping in

symbol transitions

Tx time window will create

a higher Error Vector Magnitude!

Here the Tx time window of 5µsec causes

Some mismatch between the 2 EVM

Measurements of the first SC-FDMA symbol


EVM vs. subcarrier

f

f0 f2 f1 f3

Nominal subcarriers

Each subcarrier

Modulated with

e.g. QPSK

. . . .

Integration of all

Error Vectors to

Display EVM curve

Error vector

Error vector

Note: simplified figure: in reality you

compare the waveforms due to SC-FDMA


EVM vs. subcarrier


EVM Equalizer Spectrum Flatness

2

2

*12

|)((|

|))((|*12

1

log*10)(fECA

fECAN

fP RBNRB

f

f0 f2 f1 f3

Nominal subcarriers

Subcarriers before

equalization

Amplitude Equalizer

coefficients

Integration of all

amplitude equalizer

coefficients to display

spectral flatness curve

The EVM equalizer spectrum flatness is defined as the variation in dB of the equalizer coefficients

generated by the EVM measurement process.

The EVM equalizer spectrum flatness requirement does not limit the correction applied to the signal

in the EVM measurement process but for the EVM result to be valid,

the equalizer correction that was applied must meet the

EVM equalizer spectral flatness minimum requirements.


Equalization

A(f)

f

Equalizer tries to

set same power level for

all subcarriers

1-tap equalization =

Interpreting the frequency

Selectivity as scalar factor


Calculating scalar to

amplify or attenuate


Spectrum flatness calculation

A(f)

f

Equalizer tries to

set same power level for

all subcarriers


Interpreting the frequency

Selectivity as scalar factor


Calculating scalar to

amplify or attenuate 2

2

*12

|)((|

|))((|*12

1

log*10)(fECA

fECAN

fP RBNRB


Spectral flatness


Spectrum Flatness

Frequency Range

Maximum Ripple [dB]

FUL_Meas – FUL_Low ≥ 3 MHz and FUL_High – FUL_Meas ≥ 3 MHz

(Range 1)

5.4 (p-p)

FUL_Meas – FUL_Low < 3 MHz or FUL_High – FUL_Meas < 3 MHz

(Range 2)

9.4 (p-p)

Note 1: FUL_Meas refers to the sub-carrier frequency for which the equalizer

coefficient is evaluated

Note 2: FUL_Low and FUL_High refer to each E-UTRA frequency band specified in

Table 5.2-1

FUL_High FUL_High – 3(5) MHz

< 5.4(5.4)

dBp-p

Range 1 Range 2

max(Range 1)-min(Range 2) < 6.4(7.4) dB max(Range 2)-min(Range 1) < 8.4(11.4) dB < 9.4(13.4) dBp-p


Harmonics, parasitic

emissions, intermodulation

and frequency conversion

from

modulation

process

Output RF Spectrum Emissions

Spurious domain

RB


ΔfOOB

ΔfOOB

E-UTRA Band

Worst case:

Resource Blocks allocated at

channel edge

Spectrum Emission Mask – SEM

-> measurement point by point (RBW)

Adjacent Channel Leakage Ratio – ACLR

-> integration (channel bandwidth)

occupied

bandwidth

Out-of-band emissions Spurious Emissions


Impact on SEM definition

l SEM defined for worst case scenario: RBs allocated at channel edge

l OOB emission scales with channel BW

>> a SEM per channel BW configuration

Channel

bandwidth

BWChannel

[MHz]

1.4 3 5 10 15 20

Length of OOB

domain on one

side [MHz]

5 6 10 15 20 25

5 MHz QPSK LTE Tx spectrum : +23.0 dBm / +22.0 dBm

-60

-50

-40

-30

-20

-10

0

10

20

30

-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4

offset (MHz)

level (d

Bm

/100kH

z)

1 RB MPR 0dB

5 RBs MPR 0dB

6 RBs MPR 0dB

7 RBs MPR 0dB

8 RBs MPR 0dB

9 RBs MPR 1dB

10 RBs MPR 1dB

11 RBs MPR 1dB

12 RBs MPR 1dB

13 RBs MPR 1dB

14 RBs MPR 1dB

15 RBs MPR 1dB

16 RBs MPR 1dB

18 RBs MPR 1dB

20 RBs MPR 1dB

25 RBs MPR 1dB


Adjacent Channel Leakage Ratio - ACLR

l UTRA ACLR 1+2

l EUTRA ACLR

l EUTRA measured with rectangular filter,

WCDMA measured with RRC filter

E-UTRAACLR1 UTRA ACLR2 UTRAACLR1

RB

E-UTRA channel

Channel

ΔfOOB

The purpose of this test is to verify that the UE transmitter does not cause unacceptable

interference to adjacent channels.

This is accomplished by determining the adjacent channel leakage [power] ratio (ACLR).


Adjacent Channel Leakage Ratio, ACLR

2 adjacent WCDMA

carriers, 5MHz BW

1 adjacent LTE

carrier, 20MHz BW

Active LTE

carrier, 20MHz BW


Occupied Bandwidth - OBW

99% of mean power

Occupied bandwidth is defined

as the bandwidth containing 99 %

of the total integrated mean power

of the transmitted spectrum

Transmission

Bandwidth [RB]

Transmission Bandwidth Configuration [RB]

Channel Bandwidth [MHz]

Res

ou

rce

blo

ck

Ch

an

nel e

dg

e

Ch

an

nel e

dg

e

DC carrier (downlink only)Active Resource Blocks


Spectrum Emission Mask, SEM

99% of mean power

OBW: Occupied bandwidth, defined as 99% of mean power

1 MHz RBW

SEM: Spectrum ‚Emission Mask, measured with different resolution bandwidth,

1 MHz or 30 kHz RBW

30 kHz RBW


Impact on SEM limit definition

Spectrum emission limit (dBm)/ Channel bandwidth

ΔfOOB

(MHz)

1.4

MH

z

3.0

M

Hz

5

M

Hz

10

M

Hz

15

M

Hz

20

M

Hz

Measurement

bandwidth

0-1 -10 -13 -15 -18 -20 -21 30 kHz

1-2.5 -10 -10 -10 -10 -10 -10 1 MHz

2.5-5 -25 -10 -10 -10 -10 -10 1 MHz

5-6 -25 -13 -13 -13 -13 1 MHz

6-10 -25 -13 -13 -13 1 MHz

10-15 -25 -13 -13 1 MHz

15-20 -25 -13 1 MHz

20-25 -25 1 MHz

Limits depend

on channel

bandwidth

Limits vary

dependent on offset

from assigned BW


SEM definition depends on band

Spectrum emission limit (dBm)/ Channel bandwidth

ΔfOOB

(MHz)

1.4

MHz

3.0

MHz

5

MHz

10

MHz

Measurement

bandwidth

0-0.1 -13 -13 -15 -18 30 kHz

0.1-1 -13 -13 -13 -13 100 kHz

1-2.5 -13 -13 -13 -13 1 MHz

2.5-5 -25 -13 -13 -13 1 MHz

5-6 -25 -13 -13 1 MHz

6-10 -25 -13 1 MHz

10-15 -25 1 MHz

Spectrum emission mask depends on additionally signalled band values NS_0x

e.g.

NS_07

=band 13


Transmitter Spurious Emissions

Spurious domain

RB


ΔfOOB

ΔfOOB

E-UTRA Band

Frequency Range Maximum

Level

Measurement

Bandwidth

9 kHz f < 150 kHz -36 dBm 1 kHz

150 kHz f < 30 MHz -36 dBm 10 kHz

30 MHz f < 1000 MHz -36 dBm 100 kHz

1 GHz f < 12.75 GHz -30 dBm 1 MHz

The spurious emission limits apply for the frequency

ranges that are more than ΔfOOB (MHz) from the

edge of the channel bandwidth

Channel

bandwidth

1.4

MHz

3.0

MHz

5

MHz

10

MHz

15

MHz

20

MHz

ΔfOOB (MHz) 2.8 6 10 15 20 25

…to verify that UE transmitter does not cause unacceptable interference

to other channels or other systems in terms of transmitter spurious emissions.


LTE Uplink: PUCCH

frequency

Allocation of

PUCCH only.


PUCCH measurements

PUCCH is transmitted on the 2 side

parts of the channel bandwidth


Transmit intermodulation

The transmit intermodulation performance is a measure of the capability of the transmitter

to inhibit the generation of signals in its non linear elements caused by presence of the

wanted signal and an interfering signal reaching the transmitter via the antenna.

User Equipment(s) transmitting in close vicinity of each other can produce intermodulation products,

which can fall into the UE, or eNode B receive band as an unwanted interfering signal.

The UE intermodulation attenuation is defined by the ratio of the mean power of the wanted signal

to the mean power of the intermodulation product when an interfering CW signal is added at a level

below the wanted signal at each of the transmitter antenna port with the other antenna port(s)

if any is terminated.

BWChannel (UL) 5MHz 10MHz 15MHz 20MHz

Interference Signal

Frequency Offset 5MHz 10MHz 10MHz 20MHz 15MHz 30MHz 20MHz 40MHz

Interference CW Signal

Level -40dBc

Intermodulation Product -29dBc -35dBc -29dBc -35dBc -29dBc -35dBc -29dBc -35dBc

Measurement bandwidth 4.5MHz 4.5MHz 9.0MHz 9.0MHz 13.5MHz 13.5MHz 18MHz 18MHz


Spurious Emissions

Frequency Band Measurement

Bandwidth

Maximum

level

30MHz f < 1GHz 100 kHz -57 dBm

1GHz f 12.75 GHz 1 MHz -47 dBm

General receiver spurious emission requirements

The spurious emissions power is the power of emissions generated or

amplified in a receiver that appear at the UE antenna connector.


SEM – effect of scrambling

Modulation

mapper

Transform

precoderScrambling

SC-FDMA

signal gen.

Resource

element mapper

Constant

Bit pattern

Scrambling

should

randomize the

bit stream

Scrambling

disabled +

constant bit

stream


LTE Receiver Measurements

1 Reference sensitivity level

2 Maximum input level

3 Adjacent Channel Selectivity (ACS)

4 Blocking characteristics

4.1 In-band blocking

4.2 Out-of-band blocking

4.3 Narrow band blocking

5 Spurious response

6 Intermodulation characteristics

6.1 Wide band Intermodulation

7 Spurious emissions


LTE open loop power control and RSRP reporting

UE

UE measures RSRP:

Reference Signal

Receive Power

System Information:

referenceSignalPower

[-60 .. 50]dBm

PDSCH, PUCCH or

SRS transmit power

at UE

PDSCH, PUCCH or

SRS receive power

at eNodeB

Pathloss =

referenceSignalPower - RSRP

UE reports RSRP:

back to the eNB


Reference Signal Receive Power, RSRP

R

R

R

R

Entire bandwidth

Scan over entire bandwidth,

RSRP = power of 1 symbol, as mean power


Received Signal Strength Indicator, RSSI

R

R

Entire bandwidth R

R

interferer

noise


LTE measurements

RSRP = Reference Signal Received Power

Definition Reference signal received power, the mean measured power of the

reference symbols during the measurement period.

Applicable for TBD

E-UTRA Carrier RSSI

Definition E-UTRA Carrier Received Signal Strength Indicator, comprises the total

received wideband power observed by the UE from all sources, including co-

channel serving and non-serving cells, adjacent channel interference, thermal

noise etc.

Applicable for TBD


LTE measurements: RSRQ Reference Signal Received Quality

Definition Reference Signal Received Quality (RSRQ) is defined as the ratio N×RSRP/(E-

UTRA carrier RSSI), where N is the number of RB’s of the E-UTRA carrier

RSSI measurement bandwidth. The measurements in the numerator and

denominator shall be made over the same set of resource blocks.

E-UTRA Carrier Received Signal Strength Indicator (RSSI), comprises the

linear average of the total received power (in [W]) observed only in OFDM

symbols containing reference symbols for antenna port 0, in the

measurement bandwidth, over N number of resource blocks by the UE

from all sources, including co-channel serving and non-serving cells,

adjacent channel interference, thermal noise etc.

The reference point for the RSRQ shall be the antenna connector of the UE.

If receiver diversity is in use by the UE, the reported value shall not be lower

than the corresponding RSRQ of any of the individual diversity branches.

Applicable for RRC_CONNECTED intra-frequency,

RRC_CONNECTED inter-frequency

RSRQ = RSRP

RSSI


RX Measurements – general setup

Receive Sensitivity Tests

User

definable

DL

assignment

Table

(TTI based)

Specifies DL scheduling

parameters like

RB allocation

Modulation, etc.

for every TTI (1ms)

Transmit data

according to

table on PDSCH

ACK/NACK/DTX

Counting

Receive feedback

on PUSCH

or PUCCH

+

AWGN

Blockers

Adjacent channels

requirements in terms of throughput (BLER) instead of BER

Use both

Rx Antennas


Downlink channel power for Rx tests Physical Channel EPRE Ratio

PBCH PBCH_RA = 0 dB

PBCH_RB = 0 dB

PSS PSS_RA = 0 dB

SSS SSS_RA = 0 dB

PCFICH PCFICH_RB = 0 dB

PDCCH PDCCH_RA = 0 dB

PDCCH_RB = 0 dB

PDSCH PDSCH_RA = 0 dB

PDSCH_RB = 0 dB

PHICH PHICH_RB = 0 dB

Physical Channel EPRE Ratio

PBCH PBCH_RA = A

PBCH_RB = B

PSS PSS_RA = A

SSS SSS_RA = A

PCFICH PCFICH_RB =

B

PDCCH PDCCH_RA = A

PDCCH_RB = B

PDSCH PDSCH_RA = A

PDSCH_RB = B

PHICH PHICH_RB = B

For tests where no Ref. Signal

boosting is applied

For tests where Ref. Signal

boosting is applied, e.g. ρA = -3dB


Fixed reference channels

Parameter Unit Value

Channel bandwidth MHz 1.4 3 5 10 15 20

Allocated resource blocks 6 15 25 50 75 100

Subcarriers per resource block 12 12 12 12 12 12

Allocated subframes per Radio Frame 10 10 10 10 10 10

Modulation QPSK QPSK QPSK QPSK QPSK QPSK

Target Coding Rate 1/3 1/3 1/3 1/3 1/3 1/3

Number of HARQ Processes Processes 8 8 8 8 8 8

Maximum number of HARQ transmissions 1 1 1 1 1 1

Transport block CRC Bits 24 24 24 24 24 24

Number of Code Blocks per Sub-Frame

(Note 4)

For Sub-Frames 1,2,3,4,6,7,8,9 Bits 1368 3780 6300 13800 20700 27600

For Sub-Frame 5 Bits n/a n/a n/a n/a n/a n/a

For Sub-Frame 0 Bits 528 2940 5460 12960 19860 26760

Max. Throughput averaged over 1 frame kbps 341.6 1143.2 1952.8 3952.8 6040.8 7884

UE Category 1-5 1-5 1-5 1-5 1-5 1-5

Fixed reference channels defined in TS 36.101 for receiver quality measurements


RX sensitivity level

Channel bandwidth

E-UTRA

Ban

d

1.4 MHz

(dBm)

3 MHz

(dBm)

5 MHz

(dBm)

10 MHz

(dBm)

15 MHz

(dBm)

20 MHz

(dBm)

Duplex

Mode

1 - - -100 -97 -95.2 -94 FDD

2 -104.2 -100.2 -98 -95 -93.2 -92 FDD

3 -103.2 -99.2 -97 -94 -92.2 -91 FDD

4 -106.2 -102.2 -100 -97 -95.2 -94 FDD

5 -104.2 -100.2 -98 -95 FDD

6 - - -100 -97 FDD

Criterion: throughput shall be > 95% of possible maximum

(depend on RMC)

Sensitivity depends on band,

channel bandwidth and RMC

under test

Extract from TS 36.521


Block Error Ratio and Throughput

Rx

quality DL

signal

Channel

setup Criterion: throughput shall be

> 95% of possible maximum

(depending on RMC)


Details LTE FDD signaling Rx Measurements

l Rx Measurements

l Counting

– ACKnowledgement (ACK)

– NonACKnowledgement

(NACK)

– DTX (no answer from UE)

l Calculating

l BLER (NACK/ALL)

l Throughput [kbps]


Rx measurements: BLER definition

PDCCH, scheduling info

PDSCH, as PRBS

ACK/NACK feedback

Count

#NACKs

and

calculate

BLER

Assumption is that eNB

Power = UE Rx power


Rx measurements: BLER definition

PDCCH, scheduling info

PDSCH, user data

ACK/NACK feedback

•ACK = UE properly

Receives PDCCH + PDSCH

•NACK = UE properly receives

PDCCH but does not understand

PDSCH

•DTX = UE does not understand

PDCCH

ACK relative =

NACK relative =

DTX relativ =

DTXNACKACK

ACK

###

#

DTXNACKACK

NACK

###

#

DTXNACKACK

DTX

###

#

BLER = DTXNACKACK

DTXNACK

###

##


BLER verification

Downlink error

insertion to verify

the UE reports


Transportation Block Size Index

Transportation block size

FEC User data

Flexible ratio between data and FEC = adaptive coding

TBS Idx

0

9

15

26

Modulation

QPSK

16-QAM

64-QAM

S/N

Data

rate

No change in data

rate, but in reliability


Throughput versus SNR


UE sensitivity – maximum input level

Rx Parameter Units Channel bandwidth

1.4 MHz 3 MHz 5 MHz 10 MHz 15 MHz 20 MHz

Wanted signal mean power dBm -25

Maximum input level


UE sensitivity – RF sensitivity measurement

minimum input level

Channel bandwidth

E-UTRA

Ban

d

1.4 MHz

(dBm)

3 MHz

(dBm)

5 MHz

(dBm)

10 MHz

(dBm)

15 MHz

(dBm)

20 MHz

(dBm)

Duplex

Mode

1 - - -100 -97 -95.2 -94 FDD

2 -104.2 -100.2 -98 -95 -93.2 -92 FDD

3 -103.2 -99.2 -97 -94 -92.2 -91 FDD

4 -106.2 -102.2 -100 -97 -95.2 -94 FDD

5 -104.2 -100.2 -98 -95 FDD

6 - - -100 -97 FDD

PRBS

ACK/NACK


Adjacent Channel Selectivity (ACS)

Requirement per BW, LTE interferer

AC

S=

33

dB

[1.4MHz]

1.4MHz LTE 1.4MHz LTE

Pown = - 88.5

Padj = - 57.5

1.4MHz

2dB IM Nt = - 90.5

AC

S=

33

dB

[1.4MHz]

1.4MHz LTE 1.4MHz LTE

Pown = - 88.5

- 57.5

1.4MHz

2dB IM 2dB IM Nt = - 90.5

[3MHz]

AC

S=

33

dB

3MHz LTE 3MHz LTE

Pown = - 84.5

Nt = - 86.5

Padj = - 53.5

3MHz

2dB IM

[3MHz]

AC

S=

33

dB

3MHz LTE 3MHz LTE

Pown = - 84.5

Nt = - 86.5

= - 53.5

3MHz

2dB IM 2dB IM

AC

S=

33

dB

5MHz

5MHz LTE 5MHz LTE

Pown = - 82.3

Nt = - 84.3

Padj = - 51.3

5MHz

2dB IM

AC

S=

33

dB

5MHz

5MHz LTE 5MHz LTE

Pown = - 82.3

Nt = - 84.3

= - 51.3

5MHz

2dB IM 2dB IM

AC

S=

33

dB

10MHz

5MHz LTE 10MHz LTE

Pown = - 79.3

Nt = - 81.3

Padj = - 48.3

7.5MHz

2dB IM

AC

S=

33

dB

10MHz

5MHz LTE 10MHz LTE

Pown = - 79.3

Nt = - 81.3

= - 48.3

7.5MHz

2dB IM 2dB IM

Pown = - 77.5

Nt = - 79.5

Padj = - 49.5

AC

S=

3

0d

B

15MHz

5MHz LTE 15MHz LTE

10MHz

2dB IM Pown = - 77.5

Nt = - 79.5

= - 49.5

AC

S=

3

0d

B

15MHz

5MHz LTE 15MHz LTE

10MHz

2dB IM 2dB IM

Pown= -76.3

Nt= -78.3

Padj,wcdma= -51.3

ACS=

27

dB

20MHz

5MHz LTE20MHz LTE

12.5MHz

2dB IMPown= -76.3

Nt= -78.3

Padj,wcdma= -51.3

ACS=

27

dB

20MHz

5MHz LTE20MHz LTE

12.5MHz

2dB IM2dB IM

… is a measure of a receiver's ability to receive a E-UTRA signal at its assigned channel frequency

in the presence of an adjacent channel signal at a given frequency offset from the centre frequency of

the assigned channel and with the given power


Adjacent Channel selectivity

Channel bandwidth

Rx Parameter Units 1.4 MHz 3 MHz 5 MHz 10 MHz 15 MHz 20 MHz

ACS dB 33.0 33.0 33.0 33.0 30 27

Rx Parameter Units Channel bandwidth

1.4 MHz 3 MHz 5 MHz 10 MHz 15 MHz 20 MHz

Wanted signal

mean

power

dBm

REFSENS + 14 dB

PInterferer

dBm REFSENS

+45.5d

B

REFSENS

+45.5

dB

REFSENS

+45.5dB*

REFSENS

+45.5d

B

REFSENS

+42.5d

B

REFSENS

+39.5dB

BWInterferer MHz 1.4 3 5 5 5 5

FInterferer (offset) MHz 1.4+0.0025 /

-1.4-0.0025

3+0.0075

/

-3-0.0075

5+0.0025

/

-5-0.0025

7.5+0.0075

/

-7.5-0.0075

10+0.0125

/

-10-0.0125

12.5+0.0025

/

-12.5-0.0025

Adjacent Channel Selectivity (ACS) is a measure of a receiver's ability to receive a E-UTRA

signal at its assigned channel frequency in the presence of an adjacent channel signal at a given

frequency offset from the centre frequency of the assigned channel and with the given power


Receiver performance - Blocking tests

frequency

f >> system bandwidth

fc fB

In-band blocking

Out-of-band blocking

Narrow band blocking

Throughput

shall be ≥

95%

CW interferer at a frequency,

which is less than the nominal channel spacing

5MHz LTE interferer

15MHz below to 15MHz above the UE receive band

CW interferer , more than 15MHz below to

15MHz above the UE receive band


Spurious Response Spurious response verifies the receiver's ability to receive a wanted signal on its assigned

channel frequency without exceeding a given degradation due to the presence of an unwanted

CW interfering signal at any other frequency at which a response is obtained i.e. for which

the out of band blocking limit as specified in sub-clause 7.6.2 is not met.

6/6,24max RBN

RBN

8/)2(,8max CRBsRB LN

RBN

CRBsL

For Table 7.6.2.3-2 in frequency range 1, 2 and 3, up to

exceptions are allowed for spurious response frequencies in each assigned frequency channel when measured using a 1MHz step size, where

is the number of resource blocks in the downlink transmission bandwidth configuration (see Figure 5.4.2-1).

For these exceptions the requirements of clause 7.7 Spurious Response are applicable. For Table 7.6.2.3-2 in frequency range 4, up to

exceptions are allowed for spurious response frequencies in each assigned frequency channel when measured using a 1MHz step size, where

is the number of resource blocks in the downlink transmission bandwidth configurations (see Figure 5.4.2-1) and

is the number of resource blocks allocated in the uplink. For these exceptions the requirements of clause 7.7 Spurious Response are applicable.

Out of band blocking

E-UTRA

band

Parameter Units Frequency

range 1 range 2 range 3 range 4

PInterferer dBm -44 -30 -15 -15

1, 2, 3, 4, 5,

6, 7, 8, 9, 10,

11, 12, 13,

17, 18, 19,

20, 21,

33,34,35,36,3

7,38,39,40

FInterferer

(CW) MHz

FDL_low -15 to

FDL_low -60

FDL_low -60 to

FDL_low -85

FDL_low -85 to

1 MHz -

FDL_high +15 to

FDL_high + 60

FDL_high +60 to

FDL_high +85

FDL_high +85 to

+12750 MHz -

2, 5, 12, 17 FInterferer MHz - - - FUL_low - FUL_high

NOTE: For the UE which supports both Band 11 and Band 21 the out of blocking is FFS.


Rx quality - Intermodulation

frequency

Wanted Signal C

Modulated

Interferer Imod

f

Unmodulated

Interferer Icw

f

fc fcw fmod

Throughput

shall be ≥

95%

See TS 36.101 for power and frequency offset definitions


CQI reporting

SIR

high

low

high low

≡CQIn

≡CQIn-1

≡CQIn-2

≡CQIn+2

≡CQIn+1

Prevailing conditions of SIR

Optimum throughput

if the UE reports

CQIn

SIR changes, CQI reporting must follow!

Underrated

CQI report

Overrated

CQI report

Th

rou

gh

pu

t


CQI reporting

Calculate Median CQI,

Evaluate if more than 90% of reported CQI

Are in range of median CQI ±1

Network sends median CQI – evaluate BLER on median CQI

BLER on median CQI <= 10%

Network sends CQI +1

-> BLER must be

> 10%

BLER on median CQI > 10%

Network sends CQI -1

-> BLER must be

< 10%


Rx tests – test mode UE SS

ACTIVATE TEST MODE

ACTIVATE TEST MODE COMPLETE

UE SS

CLOSE UE TEST LOOP

CLOSE UE TEST LOOP COMPLETE

Test modes defined to perform

Rx measurements, loop back

possible in test mode


UTRAN stack: 2 loop back mode defined

PHYSICAL LAYER

Medium Access Control

MAC

Packet Data Convergence

Protocol PDCP

Radio Link Control

RLC

Loop back above

PDCP, i.e. Layer 2


Test loop mode A

Uplink

and downlink

may have

various

capacity

UE Test Loop Mode A Function

u 0 ,u 1 .......u K .................u N - 1

User data

Down link

User data

Uplink

u 0 ,u 1 .......u K - 1 u 0 ,u 1 .......u K - 1

UE Test Loop Mode A Function

User data

Down link

User data

Uplink

u 0 .. u K - 1 ..u N - 1 u 0 ..u K - 1 u 0 ...u N - 1 u 0 ...u N - 1


Test loop mode B


Protocol PDCP

Loop back above

PDCP, i.e. Layer 2

buffer

ΔΤ

PDU size

must match

Delayed loop back


Throughput measurements

Max throughput

possible in SISO


Rx measurements - throughput

Throughput

Measurement,

Settings for max

throughput

for SISO:

Number of

Resource blocks

Modulation scheme

Transport block size


LTE Downlink BLER and throughput

Rx quality,

Indicating NACKs when

Lowering the RS EPRE

Of the serving cell.


Throughput + CQI in LTE

Change of

RF

condition-

> lower

data rate

UE sends

different

CQI

values


MIMO testing For MIMO, enable cell

One antenna Two antennas Four antennas

eNode B Correlation 1eNBR

1

1eNBR

1

1

1

1

*9

1*9

4*

91*

91*

94

94

91*

91

94

91

eNBR

MIMO correlation

Models from

TS 36.521


MIMO in LTE: BLER and throughput


Throughput measurements

MIMO active,

2 streams with

different data rate


Why do we need fading?

l 3GPP specifies various tests under conditions of fading

l WCDMA performance tests

l HSDPA performance tests

l LTE performance tests

l LTE reporting of channel state information tests

See CMW capability lists for details

l Evaluation of MIMO performance gain requires fading

l Correlated transmission paths in MIMO connection

l Simulation of “real life conditions” in the lab

l Comparison of processing gain for different transmission modes


Most popular MIMO scheme to increase data rates: Spatial Multiplexing

TX

Ant 1

TX

Ant 2

Time

RX

Ant 1

h11

h21

n1

r1

MIMO

RX(e.g. ZF,

MMSE,MLD)

de2

de1

Sp

ace

d1

d2

Matix B

LO

n2

r2

h12

h22

RX

Ant 2

2 X 2

MIMO

Doubles max. data rates, however, at the expense of SNR @ receiver.

Thus, according to Shannon‘s law, decrease of performance.

Makes sense for low order modulation schemes only (QPSK, 16QAM),

or in case of very good SNR conditions, e.g. for receivers close to base stations.

No increase of total transmit power, i.e. distribution of transmit power across multiple transmit antennas!


How do we test under conditions of fading?

System

simulator

Channel emulator

RF

Fading Profile


How do we test under conditions of fading?

System

simulator

Channel emulator

IQ

Out

IQ

Out

IQ

In

IQ

In

RF

Fading Profile

I/Q Interface

Option

CMW-B510x


Internal fading in LTE


BLER results with and without fading


Automatic testing: KT100 LTE + internal fading


Measurement sample (open loop SM)


BLER vs. SNR Transmit/Receive Diversity

AWGN only

MCS 7 and 10

Fading EPA 5 Hz Low

MCS 7 and 10

~2dB

~2dB


GUI – IP Settings


LTE E2E using DAU


Throughput end to end


End to end testing – ping response, RTT


What is IMS? A high level summary

l The success of the internet, using the Internet Protocol (IP) for

providing voice, data and media has been the catalyst for the

convergence of industries, services, networks and business models,

l IP provides a platform for network convergence enabling a

service provider to offer seamless access to any services,

anytime, anywhere, and with any device,

l 3GPP has taken these developments into account

with specification of IMS,

l IMS stands for IP Multimedia Subsystem,

l IMS is a global access-independent and standard-based IP

connectivity and service control architecture that enables

various types of multimedia services to end-users using

common internet-based protocols,

l Defines an architecture for the convergence of audio,

video, data and fixed and mobile networks.

How to merge IP

and cellular world??


3 GPP System Architecture Evolution

S-GW P-GW

Evolved nodeB UE

external

Evolved Packet Core

RAN

IMS

PSTN

PDN MME

Signaling interfaces

Data transport interfaces

All interfaces are packet switched

Access PDN

directly or via IMS

IMS to control

access + data

transfer


IMS Architecture


IMS protocol structure

Layer 1/2 Layer 1/2 (other IP CAN)

Layer 3 control IP / IP sec

UDP / TCP / SCTP

SIP/SDP IKE RTP MSRP

Voice

video messaging

Control plane

user plane

Mobile com specific protocols IMS specific protocols


IMS protocol structure

Sonet, SDH, PDH, Ethernet, RF link = LTE

IPv4, IPv6

Megaco

Physical

layer

link

layer

network

layer

transport

layer

application

layer

Sonet, SDH, PDH, Ethernet, RF link = LTE

e.g. PPP, AAL2/ATM, AAL5/ATM, MAC

SIP

TCP UDP

RTSP RSVP RTCP RTP

H.323

Media

Encap.

e.g. H.261, MPEG

Media Transport

Quality of Service

Signaling


ISIM: IMS SIM

UICC

universal integrated circuit card

Security keys

Public user ID

Private user ID

Home network ID

PIN Administrative data

ISIM = application on UICC

USIM for LTE access


IMS LTE

IMS Registration and Authentication Comparison with LTE

ATTACH REQUEST REGISTER

AUTHENTICATION REQ

AUTHENTICATION RSP

ATTACH ACCEPT

401 UNAUTHORIZED

REGISTER

200 OK

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SIP registration request Calculate RES, REG request

401 User not authorized 200 OK

What is IMS? Registration with IMS

l Prior to IMS registration the UE must discover an IMS entry point

(i.e. P-CSCF), which is done through an activation of a PDP context

for SIP signaling over 2G (GPRS) or 3G (WCDMA, C2K, EV-DO).

l First, there was SIM (Subscriber Identity

Module)…than there was USIM (Universal

SIM)…and now there is ISIM (IP Multimedia

Service Module),

– Public User Identity (identify a user),

– Private User Identity (users subscription),

HSS

I-CSCF

S-CSCF

P-CSCF

Retrieve S-CSCF

capabilities

Retrieve

user profile


IMS: SMS over IMS Message flow for a mobile originated SMS

RP-DATA ( SMS-SUBMIT)

RP-ACK ( SMS-SUBMIT REPORT)

RP-ACK

RP-DATA ( SMS-STATUS REPORT)

SMS Delivery

SIP MESSAGE

SIP MESSAGE

SIP MESSAGE

SIP MESSAGE

SIP 200 OK

SIP 200 OK

SIP 200 OK

SIP 200 OK


SMS over IMS

I-CSCF

S-CSCF

P-CSCF

HSS

IP based Core

Access Network,

i.e. EPC

IP-SM-GW

SMS-SC

IP short message

Gateway to connect

S-CSCF to SMS

serving centre


LTE Positioning with SUPL 2.0

UE E-SMLC

LPP over SUPL

User plane solution

LPP over RRC

Control plane solution

SET SLP

Target

Device LPP

Location

Server Assistance data

Measurements based on reference sources*

eNB

LTE radio

signal

SUPL enabled

Terminal

SUPL location

platform

Enhanced Serving

Mobile Location Center


l LTE has been designed as a fully packet-orientated, “all-IP”-

based, multi-service system with a flat network architecture,

l Technical challenges offering circuit-switched services (Voice, SMS)

via LTE

l 3GPP has defined IMS as long-term solution providing

circuit-switched services, for the short- / mid-term there is

no industry-wide consensus, but different approaches,

l Short-/mid-term: Circuit-switched fallback (CS fallback),

– SMS. “SMS over SG”, means SMS via Non-Access Stratum (NAS)

signaling,

– Voice. Fallback to 3G or 2G technology to take the call,

l VOLGA – Voice over LTE Generic Access – Call setup time increases while using CS fallback,

l OneVoice Initiative formed to push for Voice over LTE (VoLTE)

based on IMS.

Background for IMS and relation to LTE?


How to connect E-UTRAN to CS services?

l Connection via IMS: 3GPP and OneVoice initiative

l Voice over LTE Generic Access – VoLGA Forum – interim solution

l CS Fallback CSFB for voice calls to 2G or 3G services – preferred interim solution

l Evolved MSC, eMSC – CS Services via EPS – network operator proposal, interim solution

l SRVCC – Single Radio Voice Call Continuity

l SV-LTE – simultaneous voice and LTE

l OTT, Over the top – propietary solution, application based

First a big mess,

Now it seems to be OneVoice


IMS: Voice over IMS Message flow for a mobile originated call

Resource Reservation

INVITE (SDP offer)

PRACK

UPDATE (SDP)

180 RINGING

183 Session Progress (SDP offer)

200 OK (PRACK)

200 OK (UPDATE) (SDP)

PRACK

200 OK (PRACK)

Resource Reservation

200 OK (INVITE)

ACK


Voice over IMS: IMS call establishment

P-CSCF S-CSCF

1. Invite (Initial SDP Offer)


5. Offer Response

9. Response Conf (Opt SDP)

13. Conf Ack (Opt SDP)



19. Reservation Conf




22. Ringing

Originating Home Network


6. Offer Response

8. Offer Response





26. 200 OK

31. ACK 32. ACK

27. 200 OK

29. 200 OK

23. Ringing 24. Ringing

33. ACK

3. Service Control

UE

7. Authorize QoS Resources

10. Resource Reservation

25. Alert User 28. Enabling of

Media Flows

30. Start Media

Terminating Network


Voice over IMS: IMS protocol profile Codec mode Source codec bit-rate

AMR_12.20 12,20 kbit/s (GSM EFR)

AMR_10.20 10,20 kbit/s

AMR_7.95 7,95 kbit/s

AMR_7.40 7,40 kbit/s (IS-641)

AMR_6.70 6,70 kbit/s (PDC-EFR)




AMR_SID 1,80 kbit/s (see note 1)

Adaptive Multirate

Codecs are used

In VoIP over IMS


QoS class identifiers QCI

QCI Resource

Type

Priority Packet Delay

Budget

Packet Error

Loss

Rate

Example Services

1

GBR

2 100 ms 10-2 Conversational Voice

2 4 150 ms 10-3 Conversational Video (Live Streaming)

3 3 50 ms 10-3 Real Time Gaming

4 5 300 ms 10-6 Non-Conversational Video (Buffered Streaming)

5

Non-GBR

1 100 ms 10-6 IMS Signalling

6 6 300 ms

10-6

Video (Buffered Streaming)

TCP-based (e.g. www, e-mail, chat, ftp, p2p

file sharing, progressive video, etc.)

7 7 100 ms

10-3

Voice, Video (Live Streaming),

Interactive Gaming

8 8

300 ms

10-6

Video (Buffered Streaming)

TCP-based (e.g. www, e-mail, chat, ftp, p2p

file sharing, progressive video, etc.) 9 9


Voice over LTE – protocol profiles

PHYSICAL LAYER


MAC

Radio Link Control

RLC


PDCP

UDP/ TCP

IP

AMR codec

Use robust header compression or IP

Short PDCP header is used

Use RLC in UM mode

Small sequence number is used

SRB1 and 2 are supported for

DCCH + one UM DRB with QCI 1 for voice

for SIP signaling + one AM DRB QCI 5 for

SIP signaling + one AM DRB QCI 8 for

IMS traffic

TTI bundling + DRX to reduce PDCCH

Signaling + Semi-persistend scheduling

Optimize transmission of

Voice by configuring

Lower layers


IMS: Voice over IMS Interaction with EPS

l Resource reservation (QoS) can

be achieved with separate Radio

Bearers

QCI Quality of Service Class Indicator

GBR Guaranteed Bitrate

DRB Data Radio Bearer

PHY

MAC

RLC

PDCP

Default

Bearer

Dedicated

Bearer

SIP

signalling QCI = 5

Non-

GBR AM DRB

Voice QCI = 1 GBR UM DRB


VoLTE connection to CS via IMS

I-CSCF

S-CSCF

P-CSCF

HSS

MGCF BGCF

MG

PSTN

CS

network

IP based Core

Access Network,

i.e. EPC

BGW

User plane

Control plane

CS Connection via Boarder and Media Gateway of IMS

How to connect VoLTE

To legacy network?


IMS connection to CS services - arguments

l IMS can provide real end-to-end connection

l IMS defines end-to-end quality of service profiles

l IMS is completely based on Internet Protocol

l Supplementary services can be realized

l Several application servers needed

l Not widely implemented yet – many operators are reluctant

l IMS software client needed on UE side

l What happens under heavy load condition?


Radio Access Technologies today

GERAN

UTRAN

CDMA2K

1xEVDO

EUTRAN

LTE coverage is not fully up from day one

-> interworking with legacy networks is essential!!!


Voice calls in LTE

l There is one common solution: Voice over IMS l -> also named Voice over LTE VoLTE or OneVoice initiative

But….

What if IMS is not available at first rollout?

-> interim solution called Circuit Switched Fallback CSFB = handover to

2G/3G

-> or Simultaneous Voice on 1XRTT and LTE, SV-LTE = dual receiver

What is if LTE has no full coverage?

-> interworking with existing technologies, Single Radio Voice Call Continuity,

SRVCC


2G or 3G CS fallback

E-UTRAN MME IMS

Voice call

Voice over IMS is the solution,

but IMS is maybe not available in the first network roll-out.

Need for transition solution:

Circuit Switched Fall Back, CSFB move the call to 2G or 3G


2G or 3G CS fallback

UE

E-UTRAN MME

SGSN

MSC UTRAN

GERAN

Only for signalling

Only packet switched connections

Voice calls are

routed via 2G or 3G

CS

connection

as fallback

to legacy

networks


CSFB issues and questions

UE E - UTRAN MME LTE Uu S 1 - MME

GERAN

UTRAN

Um

Uu

SGSN

MSC Server

SGs

Gs

A

Iu - cs

Gb

Iu - ps

S 3

•Is it a handover command or a command to redirect to a new RAN ? i.e.

the UE selects the target cell or the EUTRAN commands the target cell

•Is there any information about the target RAN available (SysInfo)?

•Is there a packet data connection PDN active or not?

•Will the PDN be suspended or continued in the target RAN?

•Will the UE re-initiate the PDN or continue?

Handover or

Redirection?

Target cell

assigned or

selected by UE?


CS fallback options to UTRAN and GERAN

Feature

group

index, UE

indicates

CSFB

support


CS fallback to 1xRTT

E-UTRAN

MME

Serving/PDN GW

SGi

1xRTT CS Access

1xRTT MSC

1xCS IWS

S102

S11 S1-MME

S1-U

A1

A1

Tunnelled 1xRTT messages

1xCS CSFB

UE

1xCS CSFB

UE

S102 is the

reference point

between MME and

1xCS interworking

solution

Tunneling of

messages between

1xRTT MSC and UE


CS fallback - arguments

l E-UTRAN and GERAN/UTRAN coverage must overlap

l No E-UTRAN usage for voice

l No changes on EPS network required

l Gs interface MSC-SGSN not widely implemented

l Increased call setup time

l No simultaneous voice + data if 2G network/UE does not support DTM

l SMS can be used without CS fallback, via E-UTRAN


l Call setup delay

l Call drop due to handover

l Blind hand-over is used for CSFB

l Data applications are interupted

l Legacy RAN coverage needed

Why not CSFB?


Dual receiver 1xCSFB

UE

eNB for LTE

CDMA2000 cell

Circuit switched

1xRTT registration

Packet switched

EUTRAN registration

Dual receiver 1xCSFB UEs can handle separate mobility and

registration procedures 2 radio links at the same

time. UE is registered to 2 networks, no coordination required.

When CS connection in 1xRTT,

dual receiver UE leaves EUTRAN!


SV-LTE: Simultaneous CDMA200 + LTE

UE

eNB for LTE

CDMA2000 cell

Circuit switched

1xRTT connection

Packet switched

EUTRAN connection

Simultaneous Voice UEs can handle 2 radio links at the same

time. UE is registered to MME and CDMA2K independently


OTT – over the top

S-GW P-GW

Evolved nodeB UE

Evolved Packet Core

EUTRAN

PDN

Application

Voice call as application, e.g. Skype, Google talk, …


OTT – over the top - arguments

S-GW P-GW

Evolved nodeB UE

Evolved Packet Core

EUTRAN

PDN

Application

•Propietary solution, needs to be implemented in UE and AS

•Already implemented in computer networks – known application

•Support has to be accepted by operator

•No Inter-RAT handover is possible


SMS transfer in LTE

PHYSICAL LAYER


MAC

Radio Resource Control

RRC

Contr

ol &

Measure

ments

Radio Link Control

RLC


PDCP

EMM ESM User plane

Transport channels

Logical channels

Radio Bearer

Encapsulate SMS in NAS

Control message->

SMS over SG

Send SMS over IMS

Using IP protocol

SMS over IMS


CSFB circuit switched fallback – SMS transfer

SMS-SC

UE E - UTRAN MME LTE - Uu S 1 - MME

GERAN

UTRAN

Um

Uu

SGSN

MSC Server

SGs

Gs

A

Iu - cs

Gb

Iu - ps

S 3

SCTP

L2

L1

IP

L2

L1

IP

SCTP

SGs MME MSC Server

SGsAP SGsAP

SMS transfer between SMS-SC and

MME via new interface SGs.

New protocol SGs interface

application protocol

For 1xRTT it

is the S102

interface



SMS -

2. Message transfer

3. Send Routeing Info For Short Message

4. Forward Short Message 5. Paging

6. Paging 7. Paging

9b. Downlink NAS Transport

9c. Uplink NAS Transport

13. Delivery report 12. Delivery report

8. Service Request

MS/UE eNodeB MSC/VLR HLR/HSS SMS -

MME SMS-

GMSC SC

1. EPS/IMSI attach procedure

8a. Service Request

9d. Uplink Unitdata

10. Uplink NAS Transport 11. Uplink Unitdata

14. Downlink Unitdata 16. Release Request

15. Downlink NAS Transport

9a. Downlink Unitdata

Mobile terminated SMS in idle mode, SMS over SG

SGs interface

No real fallback,

because SMS

is sent over

NAS signaling



l SMS can be transferred in the signaling messages

-> so no real circuit switched fallback

l CSFB ready at LTE launch? CSFB needs SGs

interface between MME and MSC

l Roaming: no guarantee that CSFB is supported

worldwide

l Specification issues: Not clear what happens if

SMS transfer occurs at ongoing CSFB procedure

l Test scenarios: No CSFB SMS test scenarios

defined yet


Single Radio Voice Call Continuity

Problem: in first network roll-out,

there is no full LTE coverage. How to

keep call active?

=> SRVCC


SRVCC – Single Radio Voice Call Continuity

UE

E-UTRAN MME

SGSN

MSC UTRAN

GERAN

User plane after handover

Handover of voice call

to 2G or 3G

IMS

User plane before handover

SRVCC is handover from

EUTRAN to 2G/3G if no

LTE coverage



UE E-UTRAN MME MSC ServerTarget

UTRAN/GERAN

Measurement

Reports

Handover to UTRAN/GERAN

required

3GPP IMS

Initiates SRVCC for voice component

CS handover preparation

IMS Service Continuity Procedure

Handles PS-PS HO for

non-voice if needed

PS HO response to MME

(CS resources)

To eUTRAN

Coordinates SRVCC

and PS HO response Handover CMD

Handover

execution



eNodeB = EUTRAN VoLTE call

time

VoIP in PS mode

Voice call in CS mode

NodeB = UTRAN

NodeB = UTRAN

Handover to UTRAN

Radio Bearer reconfiguration:

PS to CS mode


Handover requirements l Goal is to have seamless service continuity between LTE and other Legacy

Technologies (CDMA2000, WCDMA, GSM)

l Data and Voice services

l Support of all frequency bands and a single radio solution

l Transparent signaling to allow an independent protocol evolution for both

access systems

l Impact to QoS, e.g. service interruption, should be minimized

l RAT change procedure shall limit interruption time to less than 300ms

l 3GPP changes – Ability to tunnel signaling messages between E-UTRAN and 3GPP2

– Support measurements of 3GPP2 channels from E-UTRAN

– Capability to trigger a handover to a 3GPP2 system

l 3GPP2 changes – Minimal impact on today’s available cdma2000, Rev. 0 or Rev. A access terminal

– Minimal impact to legacy, deployed cdma2000 radio access networks

– Influence on circuit switched core network should be minimized


Handovers??

l What is :

l Intra-Frequency

– Changing between cells on same frequency -> different cell ID

l Inter-Frequency

– Changing between cells on differenct frequency

l Intra-Band

– Changing between cells inside the same band

l Inter-Band

– Changing between cells in different bands

l Inter-RAT

– Changing between cells using different RAT (LTE-WCDMA, LTE-GSM,

etc.)


Handover – what to discuss?

UE

eNodeB

EUTRAN cell

Redirection command?

UTRAN cell(s)?

Will the UE initiate the

change? -> re-selection

Will the network initiate

the change? ->

redirection or handover

Mandatory

for UE

supporting

CSFB

UE reads

SysInfo

Handover command?

GERAN cell(s)?

NW sends

SysInfo of

Target?

CDMA2K cell(s)?


Handover aspects – what to discuss?

l Some keywords that appear – and to be clarified in next

slides:

l Handover?

l Cell reselection?

l Cell change order?

l Redirection?

l Network assisted cell change, NACC?

l Circuit switched fallback, CS fallback?


Mobility aspects – support from UE

l There are some UE feature groups defined. The UE reports

this in the attach procedure to the network:

– A. Support of measurements and cell reselection procedure

in idle mode

– B. Support of RRC release with redirection procedure in

connected mode

– C. Support of Network Assisted Cell Change in connected

mode

– D. Support of measurements and reporting in connected

mode

– E. Support of handover procedure in connected mode


Mobility aspects – support from UE Feature GERAN UTRAN HRPD 1xRTT EUTRAN

A. Measurements and cell reselection

procedure in E-UTRA idle mode

Supported if

GERAN

band

support is

indicated

Supported if

UTRAN

band

support is

indicated

Supported if

CDMA200

0 HRPD

band

support is

indicated

Supported if

CDMA200

0 1xRTT

band

support is

indicated

Supported for

supported

bands

B. RRC release with blind redirection

procedure in E-UTRA connected

mode

Supported if

GERAN

band

support is

indicated

Supported if

UTRAN

band

support is

indicated

Supported if

CDMA200

0 HRPD

band

support is

indicated

Supported if

CDMA200

0 1xRTT

band

support is

indicated

Supported for

supported

bands

C. Cell Change Order (with or without)

Network Assisted Cell Change) in E-

UTRA connected mode

Group 10 N.A. N.A N.A N.A.

D. Inter-frequency/RAT measurements,

reporting and measurement reporting

event B2 (for inter-RAT) in E-UTRA

connected mode

Group 23 Group 22 Group 26 Group 24 Group 25

E. Inter-frequency/RAT handover procedure

in E-UTRA connected mode

Group 9

(GSM_conn

ected

handover)

Separate UE

capability bit

defined in

TS 36.306

for PS

handover

Group 8 (PS

handover)

or Group

27

(SRVCC

handover)

Group 12 Group 11 Group 13

Table from TS36.331


LTE Radio Resource Control States

Power-up

LTE_ACTIVE (RRC_CONNECTED) • IP address assigned,

• Connected to known cell.

OUT_OF_SYNCH • DL reception possible,

• No UL transmission.

IN_SYNCH • DL reception possible,

• UL transmission possible.

LTE random access procedure

[Initial Access; allocate C-RNTI, TA-ID, IP address]


[to restore uplink synchronization]


[Transition to LTE_ACTIVE state (IN_SYNCH)]

release of C-RNTI, allocate

DRX cycle for PCH

de-allocate Tracking Area ID (TA-ID) and IP address

LTE_DETACHED • No IP address assigned,

• UE location unknown.

LTE_IDLE (RRC_IDLE) • IP address assigned,

• UE position partially known.

User Equipment (UE) LTE/eHRPD-capable terminal

1. What about

mobility, when UE

is in IDLE state?

2. What about

mobility, when UE

is in CONNECTED state?

Cell search and selection

and system information

acquisition

© Rohde&Schwarz, 2010


Mobility between LTE and WCDMA/GSM Radio Access Aspects

Handover

CELL_PCH

URA_PCH

CELL_DCH

UTRA_Idle

E-UTRA

RRC_CONNECTED

E-UTRA

RRC_IDLE

GSM_Idle/GPRS

Packet_Idle

GPRS Packet

transfer mode

GSM_Connected

Handover

Reselection Reselection

Reselection

Connection

establishment/release

Connection


Connection


CCO,

Reselection

CCO with

optional

NACC

CELL_FACH

CCO, Reselection


IRAT Procedures Redirection

1. UE has an active RF session (EPS Bearer Context, PDP Context)

2. NW releases RRC connection and indicates target RAT and RF

channel in RRC Connection Release Message

3. UE indicates active PDP Contexts during Routing Area Update

procedure on target RAT

4. NW sets up radio bearer

5. For WCDMA → LTE redirection can also be signaled in RRC

Connection Request

6. Data connection is interrupted during the procedure


Redirection

AS-security has been activated, and SRB2 with at least one DRB are setup

RRCConnectionRelease

UE EUTRAN


Redirection to UMTS

UE

eNodeB

EUTRAN cell

RRC connection release message

with RedirectedCarrierInfo to

UTRAN

NodeB(s)

UTRAN cell(s)

UE will search for

suitable cell on

UARFCN and initiate

CS connection

RRC connection release with redirection without SysInfo

Mandatory

for UE

supporting

CSFB

UE reads

SysInfo


Redirection to UMTS

UE

eNodeB

EUTRAN cell



UTRAN

NodeB

UTRAN cell

UE will go to indicated

cell and initiate CS

connection

RRC connection release with redirection with SysInfo

e-RedirectionUTRA

capability is set

by UE

Sys

Info

Rel. 9

feature UE reads

SysInfo


Redirection to GERAN

UE

eNodeB

EUTRAN cell



GSM

BTS(s)

GSM cell(s)

UE will search for

suitable cell on ARFCN

and initiate CS

connection


Mandatory

for UE

supporting

CSFB


Redirection to GERAN

UE

eNodeB

EUTRAN cell



GSM

UE will go to indicated

cell and initiate CS

connection

RRC connection release with redirection with SysInfo

e-RedirectionUTRA

capability is set

by UE

Sys

Info

Rel. 9

feature

BTS(s)

GSM cell(s)


IRAT Procedures PS Handover

l UE has an active data session (EPS Bearer Context, PDP

Context)

l NW sends handover command e.g.

l LTE → WCDMA: MobilityFrom EUTRACommand

l WCDMA → LTE: HandoverFromUTRANCommand_EUTRA

l PS radio bearer is immediately setup on target RAT


Handover (Intra-LTE)

AS-security has been activated, and SRB2 with at least one DRB are setup

RRCConnectionReconfigurationComplete

RRCConnectionReconfiguration

UE EUTRAN


Packet Switched handover to other RAN

MobilityFromEUTRACommand ::= SEQUENCE {

rrc-TransactionIdentifier RRC-TransactionIdentifier,

criticalExtensions CHOICE {

c1 CHOICE{

mobilityFromEUTRACommand-r8 MobilityFromEUTRACommand-r8-IEs,

mobilityFromEUTRACommand-r9 MobilityFromEUTRACommand-r9-IEs,

spare2 NULL, spare1 NULL

},

criticalExtensionsFuture SEQUENCE {}

}

}

Contains this information element when

Falling back to legacy networks

MobilityFromEUTRACommand

UE EUTRAN


Handover (Intra-MME/Serving Gateway)

UE Source eNB

Measurement reporting

Handover decision

Handover request

Handover request Ack

RRC connection reconfiguration

Target eNB

MME

Admission Control

Detach from old,

sync to new cell

Deliver packets

to target eNB SN Status Transfer

Data forwarding Buffer packets

from source eNB

RRC connection reconfiguration complete

Path switch Req / Ack

UE context release

Flush buffer

Release resources


Handover to UMTS: Packet switched handover

UE

eNodeB

EUTRAN cell

MobilityFromEUTRACommand message

with purpose indicator = handover

to UTRAN

EUTRAN contains targetRATmessagecontainer,

= Inter-RAT info about target cell

NodeB(s)

UTRAN cell(s)

UE will select target cell

on UARFCN and

continue PS connection

Packet Switched handover to UTRAN


HandoverfromEUTRAN – target RAT message

targetRAT-Type Standard to apply targetRAT-MessageContainer

geran GSM TS 04.18, or 3GPP TS 44.018

3GPP TS 44.060

3GPP TS 44.060

HANDOVER COMMAND

PS HANDOVER COMMAND

DTM HANDOVER COMMAND

cdma2000-

1XRTT

C.S0001 or later, C.S0007 or later,

C.S0008 or later

cdma2000-

HRPD

C.S0024 or later

utra 3GPP TS 25.331 HANDOVER TO UTRAN

COMMAND

HandoverFromEUTRAN message contains control message

of target RAT. Possible messages are:


Mobility from EUTRAN – failure case

RRC connection re-establishment


UE EUTRAN

Radio link failure

in target RAT UE will try to

Reestablish

EUTRAN connection


UE mobility in LTE (RRC CONNECTED state) Measurement configuration, related RRC messages & information elements

RRCConnectionReconfiguration …

MeasConfig

... MeasConfig MeasObjectToAddModList

ReportConfigToAddMod

QuantityConfig

measGapConfig MeasObjectToAddModList …

MeasObjectCDMA2000

Neig Cell Info

Type of CDMA network (1xRTT, HRPD),

CDMA2000 carrier configuration, search

window size, cells to add/modify/remove

from the neighboring list, cell index (up to

32 cells), PN offset…

ReportConfigToAddMod …

ReportConfigInterRAT

Periodic or event (InterRAT: B1, B2) triggered

Reporting, hysteresis (0…15 dB), # of cells to

report excluding serving cell, report interval

(120, …, 10240ms, …, 60 min), time-to-trigger,

CDMA2000 threshold (0…63)

measGapConfig gp0 (0…39), gp1 (0…79)

Two gap pattern 0 and 1, gap length is 6 ms,

using two different Transmission Gap

Repetition Period of 40 or 80 ms

How? What?

When?

Each gap starts at SFN & subframe

meeting these conditions :

SFN mod T = FLOOR(gapOffset/10)

with T = MGRP/10

Subframe = gapOffset mod 10 When to retune the receiver to measure e.g. CDMA2000 or HRPD…


Inter-RAT Handover to GERAN: cell change order

UE

eNodeB

EUTRAN cell


with purpose indicator = Cell Change Order

to GPRS

BTS(s)

GPRS cell(s)

UE will search for


and re-initiate PS

connection

Packet Switched cell change order to GPRS without NACC

(network assisted cell change)

Mandatory

for UE

supporting

CSFB

PS connection will be suspended


Inter-RAT Handover to GERAN: cell change order

UE

eNodeB

EUTRAN cell


with purpose indicator = Cell Change Order

to GPRS

BTS

GPRS cell

UE will search for


and initiate PS

connection

Packet Switched cell change order to GPRS with NACC

(network assisted cell change)

Mandatory

for UE

supporting

CSFB

Sys

Info

PS connection will be suspended


Inter-RAT Handover to GERAN: handover

UE

eNodeB

EUTRAN cell


with purpose indicator = handover

to GPRS

BTS

GPRS cell

UE will search for


and continue PS

connection

Packet Switched handover to GPRS

Mandatory

for UE

supporting

CSFB

PS connection will be handed over


LTE-RTT Handover

Circuit Switched Fallback, CSFB

Overview


3GPP Changes

l LTE Broadcast Channel

l CDMA System Time

l 1xEVDO, 1xRTT, WCDMA, GSM cell parameters

l Cell (re)selection parameters

l Broadcast as SIB Type 8 or via Dedicated RRC messages

l Tunneling

l Receiving 1xEVDO overhead messages with dual Rx ATs

l Measurement Gaps


Eg CDMA2000 Changes

l Air interface specification changes

l New protocols defined for

– Authentication: EAP-AKA

– IP Address Allocation : VSNCP

– Multiple PDN support : EMFPA

l Non-optimized and optimized handoff from LTE to eHRPD

l Preamble Initial Power for handover complete message

l Handover to 1xEV-DO Rev. B being considered

l Circuit-Switched Fallback (CS fallback) currently specified in

C.S0097-0

l Core network changes

l S101 interface – signaling interface

l S103 interface – bearer interface

l PDSN extension (now called HSGW)


Definitions cont’d

l Non-Optimized Handovers

l Without the use of tunneled signaling (S101)

l Optimized Handovers

l Less than 300ms interruption

l Uses tunneled signaling interface

l Two step process

– Pre registration / Session maintenance

– Handover preparation/handover execution

l Types of handovers

– Idle mode handover (cell re-selection)

– Active mode handover



E-UTRAN

MME

Serving/PDN GW

SGi

1xRTT CS Access

1xRTT MSC

1xCS IWS

S102

S11 S1-MME

S1-U

A1

A1

Tunnelled 1xRTT messages

1xCS CSFB

UE

1xCS CSFB

UE

S102 is the

reference point

between MME and

1xCS interworking

solution

Tunneling of

messages between

1xRTT MSC and UE



UE

eNodeB

EUTRAN cell



1xRTT

1xRTT cell(s)

UE will search for

suitable cell on

UARFCN and initiate

CS connection


Mandatory

for UE

supporting

CSFB

to 1xRTT

MME

CSFB Info

CSFB to 1xRTT

Enhancement: UE can pre-register in 1xRTT network


CS fallback to 1xRTT E-UTRAN

1xRTT

MSC1xCS IWSMMEUE

UE CONTEXT MODIFICATION REQUEST (CS Fallback Indicator)

UE decision to

perform MO call in

1xCS

RRCConnectionRelease

with redirection to 1xRTT

S-GW/

P-GW

EXTENDED SERVICE REQUEST (with service type CSFB)

UE CONTEXT MODIFICATION RESPONSE

MO call establishment in 1xRTT network

UE is EPS attached and registered with 1xRTT CS

UE context release

Optional measurement

reports

UE CONTEXT RELEASE REQUEST

Suspend Notification

Suspend Acknowledge




UE EUTRAN

HandoverFromEUTRAPreparationRequest

UE EUTRAN

ULHandoverPreparationTransfer

UE EUTRAN

enhanced 1xCSFB (e1xCSFB)

1) Prepare for

handover,

search for

1xRTT

2) Info about

1xRTT ->

tunnelled via

S102

3) Includes

1xRTT channel

assignment

Time flow





UE EUTRAN

HandoverFromEUTRAPreparationRequest

UE EUTRAN


UE EUTRAN

enhanced 1xCSFB (e1xCSFB) + concurrent HRPD handover

1) Prepare for

handover,

search for

1xRTT + HRPD

2) Trigger 2

messages with

info about

1xRTT + HRPD

3) Redirection

to 1xRTT and

handover to

HRPD

Time flow



UE EUTRAN


LTE-eHRPD Handover

Overview


InterRAT Network Architecture Eg CDMA2000 1xEVDO


EUTRAN – eHRPD non-roaming

i.e. US subscriber, connected

To home network, leaves

LTE coverage area


EUTRAN – eHRPD, roaming case

i.e. European subscriber

visiting US, connected to roaming

network and leaving LTE

coverage area


Mobility between LTE and HRPD Radio Access Aspects

HRPD active to EUTRAN is

always cell reselection

(via RRC idle)

No handover to

EUTRAN


3 Step Procedure

E-UTRAN needs

to decide, that

HO to HRPD

is required

HO preparation

Connection Request

issued by UE to

HRPD, HRPD prepares

for the arrival of the UE

HO execution

Traffic Channel Assignment

command is delivered

to UE, re-tune radio to

HRPD channel, acquire

HRPD channel, session

configuration

UE attached

to E-UTRAN

Ability of pre-

registration is

indicated

on PBCCH

Pre-registration

• Reduces time for cell re-selection or handover

• Reduces risk of radio link failure

Video over LTE Testing the next step in the end user experience


l Cisco quote 06/2011

l Internet video is now 40 percent of

consumer Internet traffic, and will reach

62 percent by the end of 2015, not

including the amount of video ex-

changed through P2P file sharing. The

sum of all forms of video (TV, video

on demand [VoD], Internet, and P2P)

will continue to be approximately 90

percent of global consumer traffic by 2015.

l IDC quote 06/2011

l The fast-growing smartphone market, which will

grow more than four times the rate of the overall

mobile phone market this year, is being fuelled

by falling average selling prices, increased

phone functionality, and lower-cost data plans

among other factors, which make the devices

more accessible to a wider range of users.

Introduction


Node B

Internet

SGW PGW

MME PCRF

EPC / IMS

Node B

Impact due to

l Multipath propagation

l Speed

l …

Impact due to

l Packet delay

l Packet jitter

l Packet loss

l …

Introduction Network view


l Main use cases from a test engineer (operator, manufacturer) perspective:

l Exploring the performance of mobile equipment from the end user perspective

l Measuring E2E throughput with realistic radio conditions

l Evaluating mobility performance

Introduction Testing real life conditions in the lab

l Important aspect for end user perspective: Error free video reception

R&S®CMW500

emulates LTE

network

R&S®AMU200

baseband fader

simulates real life

radio conditions

Contest SW

provides

automation

and reporting

capabilities

CMW-PQA


Video transmission over LTE Video quality…

l … is the perceived degradation of a processed video in

comparison to an ideal reference or the reality

l … can be used as an evaluation criteria for any kind of video

transmission or processing system as signal impairments will

happen in different stages

l … can be categorized in two basic types of video quality

assessment

l Subjective quality assessment

l Objective quality assessment


Receiver

Video transmission over LTE The video processing chain and possible sources for video degradation

Encoder

Uncompressed video

SDI

SMPTE249/292/424

Redundant

information (static

image parts) and

irrelevant data

(details) is omitted

Decoder TX RX Video processor

Output on

screen Restoring the video

information; i.e. the

picture sequence

including redundant

data

Scaling and

conversion to output

format

Transmission

link

(IP, cellular,

broadcast, etc.)

• Encoding artifacts

(blocking)

• Video / audio delay

• Buffer rules are

violated

Impairments on the

transmission link

can cause loss of

information despite

active error

correction

The decoder is usually the less

critical component. But in

conjunction with the video

processor, errors during the

conversion process (e.g. de-

interlacing) are possible


Video transmission over LTE Subjective quality assessment

l Subjective video quality assessments are defined in ITU-T recommendation BT.500

l Example procedure:

A group of trained experts judge the video quality in a scale ranging from bad to excellent. The assessments are averaged and result in to a Mean Opinion Score (MOS).

l Advantages:

l Subjective assessment provides the best results, as the ultimate measure for video quality is the human eye

l Disadvantages:

l Time consuming and expensive

l Automation not possible

Mean Opinion Score (MOS)

MOS Quality

5 Excellent

4 Good

3 Fair

2 Poor

1 Bad


Video transmission over LTE Objective quality assessment

l Mathematical calculation that approximate averaged results of

subjective quality assessment

l Divided into three categories:

l Full reference methods (FR)

l Reduced reference methods (RR)

l No-reference methods (NR)

l Advantage:

l Assessment automation is possible for various applications

l Disadvantages:

l Correlation with the actual perceived video quality is not always ensured

l Many different metrics for specific purposes exist


l Most commonly used for quality measurements for image compression.

l Simple mathematical calculation but poor correlation with subjective methods:

l Digital pixel values do not exactly represent the light stimulus on the human eye

l The summation is averaging errors without weighting them

l The same PSNR values may result from different kind of structural errors

Video transmission over LTE Objective metric – peak signal-to-noise ratio (PSNR)

I(i,j) = original pixel

K(i,j) = reconstructed pixel

MAX = maximum possible pixel value

Unit: dB

Value range: 0 - ∞ dB; the higher, the better

21

0

1

0

2

10

),(),(1

)(log10

jiKjiImn

MSE

MSE

MAXPSNR

n

j

m

i

I


l Improvement to traditional methods for quality measurements to improve consistency with human eye perception.

l Complex mathematical calculation but fairly good correlation with subjective methods.

Video transmission over LTE Objective metric – structural similarity (SSIM)

Reference:

Z. Wang, A. C. Bovik, H. R. Sheikh and E. P. Simoncelli, "Image quality assessment: From

error visibility to structural similarity," IEEE Transactions on Image Processing, vol. 13, no. 4,

pp. 600-612, Apr. 2004.

Luminance

Measurement

Luminance

Measurement

Luminance

Comparison

Contrast

Comparison

Structure

Comparison

Combination

Contrast

Measurement

Contrast

Measurement

+

+

÷

÷

Signal x

Signal y

Similarity

Measure

))((

)2)(2(),(

2

22

1

22

21

CC

CCyxSSIM

yxyx

xyyx

Unit: -

Value range: 0 - 1; the higher, the better

http://www.cns.nyu.edu/~zwang/files/papers/ssim.html


http://en.wikipedia.org/w/index.php?title=IEEE_Transactions_on_Image_Processing&action=edit&redlink=1


Video transmission over LTE Correlation of objective metric with MOS

(MSSIM = Mean SSIM)

Reference:

Z. Wang, A. C. Bovik, H. R. Sheikh and E. P. Simoncelli, "Image quality assessment: From

error visibility to structural similarity," IEEE Transactions on Image Processing, vol. 13, no. 4,

pp. 600-612, Apr. 2004.



http://en.wikipedia.org/w/index.php?title=IEEE_Transactions_on_Image_Processing&action=edit&redlink=1


Video transmission over LTE Metric – visible error

0

0,2

0,4

0,6

0,8

1

1,2

1 3 5 7 9 11 13 15 17 19 21 23

Frame

SS

IM

Not visible

Not visible

Visible 1

Visible 2

6 Frames Visible Error

l The shown objective metrics and their correlation with MOS are

calculated frame based

l Temporal masking effects need to be considered:

l Additional condition: e.g. for at least 6 frames SSIM below 0.7 (25 fps video)


Video transmission over LTE Demo


Video transmission over LTE Testing real life conditions in the lab

PC

Contest

TC Control

Video

via MHL

or HDMI

RF


Video transmission over LTE R&S®VTE Video Tester

l Source, sink and dongle testing on MHL 1.2 interfaces and in the future also HDMI 1.4c, etc.

l Realtime difference picture analysis for testing video transmissions over LTE

l Combined protocol testing and audio/video analysis

l Future-ready, modular platform accommodating up to three test modules

l Localized touchscreen user interface

l Integrated test automation and report generation

R&S®VTE Video Tester


Video transmission over LTE Mobile high definition link (MHL)

MHL is…

l the leading audio/video interface for mobile devices

l utilizes the existing Micro-USB connector

l provides power to the mobile device

l Single Transition Minimized Differential Signaling (TMDS) channel:

l Carries video, audio and auxiliary data

l Bit stream is modulated by a clock signal

l Single-wire Control Bus (CBUS)

l Configuration and status exchange

l Replaces the DDC bus in HDMI

l Carries the MHL Sideband Channel (MSC) which provides high level control functions

l VBUS and associated ground

l Provide power between sink and source

l 5V, max. 0.5 A


Summary

l Video and voice are important services gaining momentum for

the fastest developing radio access technology ever - LTE

l Beside LTE functionality, testing voice/video quality is

essential to judge a good receiver implementation

l R&S provides you with profound expertise and

test solutions on both aspects

l Complete LTE test portfolio ranging from early R&D via IOT

and field testing until conformance and production

l Supplier of a complete range of TV broadcasting transmission,

monitoring and measurement equipment


There will be enough topics

for future trainings

Thank you for your attention!

Comments and questions welcome!

LTE Measurement: How to test a device

Technology

Transcript of LTE Measurement: How to test a device