LTE measurements.pdf

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

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

November 2012 | LTE measurements|

2

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


3

LTE: EPS Bearer E-UTRAN

UE

EPC

eNB

S-GW

Internet

P-GW

Peer Entity

End-to-end Service

EPS Bearer

Radio Bearer

Radio

External Bearer

S1 Bearer

S5/S8 Bearer

S1

S5/S8


Gi

4

Mobile Radio Testing Adjust the downlink signal to how uplink is received

Generate downlink signal and send control commands

Perform RF measurements on received uplink

Core network

A mobile radio tester emulates a base station November 2012 | LTE measurements|

5

Mobile Radio Testing Generate downlink signal and send signaling information

Generate downlink signal No signaling

Signaling testing


Control PC

Non-Signaling testing

6

LTE measurements general aspects


7

LTE RF Testing Aspects

UE requirements according to 3GPP TS 36.521 Power

Transmit signal quality

 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

36.521: User Equipment (UE) radio transmission and reception

Frequency

error Modulation quality, EVM Carrier Leakage In-Band Emission for non allocated RB EVM equalizer spectrum flatness

Output RF spectrum emissions  Occupied

bandwidth  Out of band emissions  Spectrum emisssion mask  Additional Spectrum emission mask  Adjacent Channel Leakage Ratio

Transmit Intermodulation


8


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 November 2012 | LTE measurements|

9


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


10


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


11

LTE RF Measurements – regional requirements l l

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


12

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

1.4 MHz

3 MHz

1

5 MHz

10 MHz

15 MHz

20 MHz

Yes

Yes

Yes

Yes Yes[1]

2

Yes

Yes

Yes

Yes

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]

7

Yes

Yes

Yes

Yes[1]

Yes

Yes[1]

9

Yes

Yes

Yes[1]

Yes[1]

10

Yes

Yes

Yes

Yes

Yes

Yes[1]

Yes[1]

Yes[1]

13

Yes[1]

Yes[1]

14

Yes[1]

Yes[1]

Yes[1]

Yes[1]

33

Yes

Yes

Yes

34

Yes

Yes

Yes

8

Yes

Yes

11 12

Yes

Yes

... 17 ...

Not every channel bandwidth for every band! Yes

35

Yes

Yes

Yes

Yes

Yes

Yes

36

Yes

Yes

Yes

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.


13

RF power

Tests performed at “low, mid and highest frequency” Nominal frequency described by EARFCN (E-UTRA Absolute Radio Frequency Channel Number)

lowest EARFCN possible and 1 RB at position 0

RF power

Frequency = whole LTE band mid EARFCN and 1 RB at position 0

RF power

Frequency

Highest EARFCN and 1 RB at max position Frequency November 2012 | LTE measurements|

14

Test Environment – Test System Uncertainty 36.101 / 36.508 • Temperature/Humidity -normal conditions +15C to +35C, relative humidity 25 % to 75 % -extreme conditions -10C to +55C (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

6.2.2. UE Maximum Output Power

Minimum Requirement in TS 36.101

Test Tolerance (TT)

Test Requirement in TS 36.5211

Power class 1: [FFS] Power class 2: [FFS] Power class 3: 23dBm ±2 dB Power class 4: [FFS]

0.7 dB 0.7 dB 0.7 dB 0.7 dB

Formula: Upper limit + TT, Lower limit - TT Power class 1: [FFS] Power class 2: [FFS] Power class 3: 23dBm ±2.7 dB Power class 4: [FFS]


15

LTE RF measurements on base stations


16

OFDM risk: Degradation Channel (ideal)

rl  n 

sl  n 

Samples

1 TMC

f f0

f1

f2

f0

f3


17

f1

f2

f3

OFDM risk: Degradation due to Frequency Offset Channel

e j 2fn rl  n 

sl  n 

Samples

f

f f0

f1

f2

f0

f3


18

f1

f2

f3

OFDM risk: Degradation due to Clock Offset Channel

sl  n 

rl  n 



Samples

f  k

f f0

f1

f2

f0

f3


19

f1

f2

f3

Subcarrier zero handling Subcarrier 0 or DC subcarrier causes problems in DAC for direct receiver strategies, DC offset!

Downlink: sl( p ) t  

1





DL RB k   N RB N sc / 2



f-1

DL RB N RB N sc / 2   j 2kf t  N CP ,l Ts  ( p) a k (  ) ,l  e   ak( (p)) ,l  e j 2kf t  NCP ,lTs 

f+1

DC subcarrier, suppressed

k 1

1/TSYMBOL=15kHz

Uplink: sl t  

N RBULNscRB / 2 1 



UL RB k   N RB N sc / 2

a k (  ) ,l  e



j 2 k 1 2 f t  N CP ,l Ts 

f-1

½ subcarrier offset November 2012 | LTE measurements|

f0

f1

DC subcarrier 20

f

LTE: DC subcarrier usage

DC subcarrier or subcarrier 0 is not used in downlink! November 2012 | LTE measurements|

21

DC offset – possible reasons DC offset originated by mixer:

fRX=fLO+fBB+fLO_ɛ fLO_ɛ

1st mixer

fBB=fRx-fLO fLO –fLO_ɛ=DC

fLO

fBB + DC Non-linearities of Amplifier also cause DC in the signal

PLL

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! November 2012 | LTE measurements|

22

Base station test models Parameter

1.4 MHz

3 MHz

5 MHz

10 MHz

15 MHz

20 MHz

1

1

1

1

1

1

0.000

0.000

0.000

0.000

0.000

0.000

-inf

-inf

-inf

-inf

-inf

-inf

0.000

0.000

0.000

0.000

0.000

0.000

-inf

-inf

-inf

-inf

-inf

-inf

Reference, Synchronisation Signals RS boosting, PB = EB/EA Synchronisation signal EPRE / ERS [dB] Reserved EPRE / ERS [dB] PBCH PBCH EPRE / ERS [dB] Reserved EPRE / ERS [dB] PCFICH # of symbols used for control channels PCFICH EPRE / ERS [dB]

2

1

1

1

1

1

3.222

0

0

0

0

0

1

1

1

2

2

3

PHICH # of PHICH groups # of PHICH per group

2

2

2

2

2

2

-3.010

-3.010

-3.010

-3.010

-3.010

-3.010

0

0

0

0

0

0

# 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 REGs added for padding

5

5

7

0

14

7

0.792

2.290

1.880

1.065

1.488

1.195

-inf

-inf

-inf

-inf

-inf

-inf

# 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

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

PHICH BPSK symbol power / ERS [dB] PHICH group EPRE / ERS [dB] PDCCH

PDCCH REG EPRE / ERS [dB] REG EPRE / ERS [dB] PDSCH



23

TS 36.141 Defines several Test models For base station e.g. E-TM1.1

Base station unwanted emissions Spurious emissions ACLR •Adjacent channel leakage •Operating band unwanted emissions Spurious domain

ΔfOOB

Channel bandwidth

ΔfOOB

Spurious domain

RB

E-UTRA Band

Worst case: Ressource Blocks allocated at channel edge November 2012 | LTE measurements|

24

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.

Large bandwidth

Limit is either -13 / -15dBm absolute or as above November 2012 | LTE measurements|

25

Adjacent channel leakage power ratio


26

ACLR measurement Ref

0 dBm

Att

25 dB

* RBW

10 kHz

VBW

30 kHz

SWT 250 ms

*

0

A

-10 1 AP VIEW

-20

2 AP VIEW

-30

3 AP CLRWR

-40

-50

EXT 3DB

-60

UTRAACLR1 = 33 dB

UTRAACLR2 = 36 dB

UTRAACLR2bis = 43 dB

-70

-80

-90

Additional requirement for E-UTRA frequency band I, signaled by network to the UE

-100

Center

1.947 GHz

fUTRA, ACLR2

Date: 21.AUG.2008

15:51:00

2.5 MHz/

fUTRA, ACLR1

Span

fCarrier


27

25 MHz

Operating band unwanted emissions Narrow bandwidth Frequency offset of measurement filter -3dB point, f

Frequency offset of measurement filter centre frequency, f_offset

Minimum requirement

0 MHz  f < 5 MHz

0.05 MHz  f_offset < 5.05 MHz

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

7  f _ offset   7dBm     0.05 dB 5  MHz 

Measurem ent bandwidth (Note 1) 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! November 2012 | LTE measurements|

28

Operating band unwanted emissions


29

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

Measurement Bandwidth

Note

9kHz - 150kHz

1 kHz

Note 1

150kHz - 30MHz

10 kHz

Note 1

100 kHz

Note 1

1 MHz

Note 2

30MHz - 1GHz

Maximum level

-13 dBm

1GHz – 12.75 GHz NOTE 1: NOTE 2:

Bandwidth as in ITU-R SM.329 [5] , s4.1 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 November 2012 | LTE measurements|

30

Spurious emissions – operating band excluded


31

Base station maximum power 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. BS

External PA

External device e.g. TX filter

(if any)

(if any)

cabinet

Test port A

Normal port for measurements

Towards antenna connector



Test port B

Port to be used for measurements in case external equipment is used November 2012 | LTE measurements|

32

LTE – DVB interference scenarios Adjacent channel leakage of Basestation x into DTT channel N is point of interest

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 November 2012 | LTE measurements|

33

Base station receiver test Example: Rx test, moving condition

70% of required throughput of FRC, Fixed Reference Channel


34

Base station receiver test – HARQ multiplexing

UE sends PUSCH with alternating data and data with multiplexed ACK


35

Base station test – power dynamics Synchronisation time/frequency BS under Test

FFT 2048 RFcorrection

CPremov

100 RBs, 1200 sub carr

Per subcarrier Ampl. /Phase correction

Symbol Detection / decoding

EVM

Resource element Tx power: Distinguish: •OFDM symbol •Reference symbol

RETP


36

Downlink Power Reference Signal: Cell-specific referenceSignalPower (-60…+50dBm), signaled in SIB Type 2

PDCCH power depending on ρB/ρA

PDSCH power to RS, where NO reference signals are present, is UE specific and signaled by higher layers as PA. For PDSCH power in same symbol as reference signal an additional cell specific offset is applied, that is signaled by higher layers as PB.

[Power] -50.00 dBm

2011 © Rohde&Schwarz

PA = -4.77 dB -54.77 dBm

PB = 3 (-3.98 dB) -58.75 dBm

0

1

2

3

4

5

6

7

8

9

11

10

12

13

[Time]

OFDM symbols

RS EPRE = Reference Signal Energy per Resource Element EPRE PDSCH   A / B  EPRE RS

Reference signal power = linear average of all Ref. Symbols over whole channel bandwidth B  PB   A


 A  PA (with some exeptions for MIMO)

37

Base station test – output power dynamics Measure avg OFDM symbol power + Compare active and non-active case Ref. Symbol, always on OFDM Symbol not active! OFDM Symbol active! PDSCH # of 64QAM PDSCH PRBs within a slot for which EVM is measured

1


0

0

0

0

0

0

# of PDSCH PRBs which are not allocated

5

14

24

49

74

99

Test model: E-TM2 Only 1 RB allocated

1

1

1

1

Test model: E-TM3.1 All RB allocated

1

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


6

15

38

25

50

75

100

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 November 2012 | LTE measurements|

39

LTE RF measurements on user equipment UEs


40

LTE Transmitter Measurements 1 1.1 1.2 1.3 1.4 2 2.1 2.2 2.3 2.3.1 2.3.2 2.3.3 2.4 2.4.1 2.4.2 2.4.3 3 3.1 3.2 3.2.1 3.2.2 3.2.3 3.2.4 4 4.1 4.2 4.2.1 4.2.2 4.2.3 4.3 4.3.1 4.3.2 4.3.3 5

Transmit power UE Maximum Output Power Maximum Power Reduction (MPR) Additional Maximum Power Reduction (A-MPR) Configured UE transmitted Output Power Output Power Dynamics Minimum Output Power Transmit OFF power ON/OFF time mask General ON/OFF time mask PRACH time mask SRS time mask Power Control Power Control Absolute power tolerance Power Control Relative power tolerance Aggregate power control tolerance Transmit signal quality Frequency Error Transmit modulation Error Vector Magnitude (EVM) Carrier leakage In-band emissions for non allocated RB EVM equalizer spectrum flatness Output RF spectrum emissions Occupied bandwidth Out of band emission Spectrum Emission Mask Additional Spectrum Emission Mask Adjacent Channel Leakage power Ratio Spurious emissions Transmitter Spurious emissions Spurious emission band UE co-existence Additional spurious emissions Transmit intermodulation


41

UE Signal quality – symbolic structure of mobile radio tester MRT Test equipment Rx … … …

DUT

RF correction

l l l l l

IDFT

FFT

… … …

l

TxRx equalizer

Inbandemmissions

Carrier Frequency error EVM (Error Vector Magnitude) Origin offset + IQ offset Unwanted emissions, falling into non allocated resource blocks. Inband transmission Spectrum flatness November 2012 | LTE measurements|

42

EVM meas.

UL Power Control: Overview UL-Power Control is a combination of: l Open-loop:

UE estimates the DL-Pathloss and compensates it for the UL l Closed-loop:

in addition, the eNB controls directly the ULPower through powercontrol commands transmitted on the DL


43

PUSCH power control l

Power level [dBm] of PUSCH is calculated every subframe i based on the following formula out of TS 36.213

MPR Maximum allowed UE power in this particular cell, but at maximum +23 dBm1)

Combination of cell- and UE-specific components configured by L3

Number of allocated resource blocks (RB)

Transmit power for PUSCH in subframe i in dBm

Bandwidth factor 1)

Cell-specific parameter configured by L3

PUSCH transport format

Downlink path loss estimate

Power control adjustment derived from TPC command received in subframe (i-4)

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

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


44

Pcmax definition „lower“ tolerance

„upper“ tolerance

„corrected“ UE power

PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H) PCMAX_L = min{PEMAX_L, PUMAX }

PCMAX_H = min{PEMAX_H, PPowerClass} Max. power permitted in cell

Max. power permitted in cell, considering bandwidth confinement

Max. power for UE

Max. power for UE, considering maximum power reduction


45

Pcmax definition PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H), lPCMAX_L = min{PEMAX_L , PUMAX }, 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, PPowerClass + 2dB

23dBm -1.5dB

PPowerClass - 2dB

-1.5dB

FUL_high- 4MHz

FUL_low November 2012 | LTE measurements|

46

FUL_high

Pcmax definition PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H), PCMAX_L = min{PEMAX_L , PUMAX }, l

PUMAX corresponds to maximum power (depending on power class, taking into account Maximum Power Reduction MPR and additional A-MPR UE may decide to reduce power

UE power class = 23dBm ±2 dB

Network may signal bandwidth restriction NS_0x


47

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 November 2012 | LTE measurements|

48

UE Additional Maximum Power Reduction A-MPR Additional maximum power reduction requirements can be signaled by the network as NS value in SIB2

Network Signaling value

Requirements (sub-clause)

E-UTRA Band

Channel Bandwidth (MHz)

Resource Blocks

A-MPR (dB)

NS_01

NA

NA

NA

NA

NA

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

> 29

≤1

> 39

≤2

> 44

≤3

NS_03

(IE AdditionalSpectrumEmission)

NS_08

[NS_09]

6.6.3.3.3.3

19

10, 15

6.6.3.3.3.4

21

TBD

TBD

TBD

-

-

-

-

-

.. NS_32


49

PUSCH power control

Transmit output power ( PUMAX), cont’d. 3GPP Band 13 746

756

777

DL

Network Signalling Value

Requiremen ts (sub-clause)

E-UTRA Band

UL

Channel bandwidth (MHz)

Resources Blocks

A-MPR (dB)

…

…

…

…

…

…

NS_07

6.6.2.2.3 6.6.3.3.2

13

10

…

Indicates the lowest RB … … index of transmitted resource blocks

Table 6.2.4 -2

…

l

Table 6.2.4 -2

…

…

Region A 0 – 12

RBStart Defines the length of a contiguous RB allocation

787

Region B

Region C

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

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. November 2012 | LTE measurements| 50

Pcmax definition – tolerance values PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H)

Tolerance is depending on power levels

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


51


PCMAX_H = min{PEMAX_H , PPowerClass }, 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

UE power class = 23dBm ±2 dB November 2012 | LTE measurements|

52


PCMAX_H = min{PEMAX_H , PPowerClass }, 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,

EUTRA band

Class 1 (dB m)

Tolerance (dB)

Class 2 (dBm)

Tolerance (dB)

Class 3 (dBm )

Tolerance (dB)

1

23

±2

2

23

±22

…

23

±22

40

23

±2


53

Class 4 (dBm)

Tolerance (dB)

Pcmax value for power control - analogies PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H) PCMAX_L = min{PEMAX_L, PUMAX }

PCMAX_H = min{PEMAX_H, PPowerClass}

Maximum speed = 280 km/h =PPowerClass

=PEMAX_H

=PEMAX_L

Under those conditions, I shall drive more carefully! Not going to the max seed! -> speed reduction =PUMAX


54

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


55

RF power

Resource Blocks number and maximum RF power 1 active resource block (RB),

Nominal band width 10 MHz = 50 RB’s

RF power

Frequency

One active resource block (RB) provides maximum absolute RF power More RB’s in use will be at lower RF power in order to create same integrated power

RF power

Frequency

MPR

Additionally, MPR (Max. Power Reduction) and AMPR are defined

Frequency November 2012 | LTE measurements|

56

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

Temperature/Voltage high/low

Test Parameters for Channel Bandwidths Downlink Configuration Ch BW

N/A for Max UE output power testing

Uplink Configuration 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


57

UE maximum power PPowerClass + 2dB

23dBm PPowerClass - 2dB

FUL_low

maximum output power for any transmission bandwidth within the channel bandwidth November 2012 | LTE measurements|

58

FUL_high

UE maximum power – careful at band edge! PPowerClass + 2dB

23dBm PPowerClass - 2dB

-1.5dB

FUL_low

FUL_low+4MHz

FUL_high- 4MHz

-1.5dB

FUL_high

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 November 2012 | LTE measurements|

59

UE maximum power - examples Example 1: No maximum power reduction by higher layers PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H) PCMAX_L = min{PEMAX_L, PUMAX } Max. power permitted in cell, considering bandwidth confinement

Max. power for UE, considering maximum power reduction

PCMAX_H = min{PEMAX_H, PPowerClass} Max. power permitted in cell

Max. power for UE

T(PCMAX_L) = T(PCMAX_H)=2dB PEMAX_L = none PUMAX = power class 3 = +23 dBm PEMAX_H = none PPowerClass = power class 3 = +23 dBm 25dBm PPowerClass + 2dB 23dBm PPowerClass - 2dB

FUL_high

FUL_low November 2012 | LTE measurements|

60

21dBm

UE maximum power - examples Example 2: max cell power = 0 dBm + band edge maximum power reduction PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H) PCMAX_L = min{PEMAX_L, PUMAX }

PEMAX_L = 0dBm -1.5 dB relaxation = -1.5dBm PUMAX = power class 3 – band relaxation = +21.5 dBm

PCMAX_H = min{PEMAX_H, PPowerClass} PEMAX_H = 0 dBm PPowerClass = power class 3 = +23 dBm

PCMAX_L=-1.5dBm

PCMAX_H=0 dBm T(PCMAX_L) = T(PCMAX_H)=7dB PCMAX_H + 7dB

+7dBm 0 dBm

PCMAX_L - 7dB

FUL_low

FUL_high

FUL_low+4MHz November 2012 | LTE measurements|

61

-8.5dBm

UE maximum power - examples 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 MPR = 1dB, A-MPR = 12 dB, no band edge relaxation

PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H) PCMAX_L = min{PEMAX_L, PUMAX } PEMAX_L = none PUMAX = power class 3 – MPR – A.MPR = +10 dBm PCMAX_L=10 dBm

PCMAX_H = min{PEMAX_H, PPowerClass} PEMAX_H = none PPowerClass = power class 3 = +23 dBm

T(PCMAX_L) = 6 dB T(PCMAX_H)=2dB

PCMAX_H=23 dBm PCMAX_H +2dB

PCMAX_L - 6dB

RB start = 13

FUL_high

12 Resource blocks November 2012 | LTE measurements|

62

+25dBm 23 dBm

4 dBm

UE maximum power - examples Example 4: band edge power relaxation – no higher layer reduction signalled QPSK, 15 RBs allocated, Band 2, RB allocated at band edge MPR = 1dB, A-MPR = 1 dB, band edge relaxation of 1.5dB PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H) PCMAX_H = min{PEMAX_H, PPowerClass}

PCMAX_L = min{PEMAX_L, PUMAX } PEMAX_L =none PUMAX = power class 3 – MPR-A-MPR-band relaxation = 23-1-1-1.5=+19.5 dBm PCMAX_L=19.5dBm

PEMAX_H = none PPowerClass = power class 3 = +23 dBm PCMAX_H= 23 dBm PCMAX_H + 2dB

T(PCMAX_L) = 3.5 dB T(PCMAX_H)=2dB

+25 dBm 23 dBm

PCMAX_L – 3.5 dB

FUL_low

PCMAX_L – 2 dB

+16 dBm

FUL_high

FUL_low+4MHz November 2012 | LTE measurements|

63

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


64

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

10 MHz

15 MHz

20 MHz

13.5 MHz

18 MHz

-50 dBm

Transmit OFF power

Measurement bandwidth

5 MHz

1.08 MHz

2.7 MHz

4.5 MHz


9.0 MHz

65

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


66

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.


67

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


68

Configured UE transmitted Output Power

IE P-Max (SIB1) = PEMAX

To verify that UE follows rules sent via system information, SIB Test: set P-Max to -10, 10 and 15 dBm, measure PCMAX Channel bandwidth / maximum output power 1.4 MHz

3.0 MHz

5 MHz

10 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


69

15 MHz

20 MHz

LTE Power versus time RB allocation is main source for power change

Not scheduled Resource block

PPUSCH (i)  min{PMAX ,10 log10 (M PUSCH (i))  PO_PUSCH ( j )    PL   TF (TF (i))  f (i)} Bandwidth allocation

Given by higher layers TPC commands or not used


70

Accumulative TPC commands

TPC Command Field In DCI format 0/3

Accumulated  PUSCH [dB]

0

-1

1

0

2

1

3

3

2

minimum power in LTE


71

Absolute TPC commands PPUSCH (i)  min{ PMAX ,10 log 10 ( M PUSCH (i))  PO_PUSCH ( j )    PL   TF (TF (i))  f (i)}

TPC Command Field In DCI format 0/3

Absolute  PUSCH [dB] only DCI format 0

0

-4

1

-1

2

1

3

4

Pm -1 -4


72

Relative Power Control Power pattern B

Power pattern A

RB change RB change

0 .. 1

9

sub-frame# 2 3

4

radio frame

Power pattern C

9

sub-frame# 2 3

9

sub-frame# 2 3

4

radio frame

l The purpose of this test is to verify RB change

0 .. 1

0 .. 1

4

radio frame

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 subframes is ≤ 20 ms.


73

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.


74

Power Control – Relative Power Tolerance l

Various power ramping patterns are defined

ramping down

alternating

ramping up


75

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 subframes [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

PRACH [dB]

P

Power tolerance relative given by table time November 2012 | LTE measurements|

76

UE power measurements – relative power change Power

Power

FDD test patterns

0 1

Sub-test

TDD test patterns

9 sub-frame#

Uplink RB allocation

0

TPC command

2 3

7

8

Expected power step size (Up or down)

test for each bandwidth, here 10MHz

9 sub-frame#

Power step size range (Up or down)

PUSCH/

ΔP [dB]

ΔP [dB]

[dB]

1

ΔP < 2

1 ± (1.7)

A

Fixed = 25

Alternating TPC = +/-1dB

B

Alternating 10 and 18

TPC=0dB

2.55

2 ≤ ΔP < 3

2.55 ± (3.7)

C


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


TPC=0dB

13.98

10 ≤ ΔP < 15

13.98 ± (5.7)

F


TPC=0dB

16.99

15 ≤ ΔP

16.99 ± (6.7)


77

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.

Tolerated UE power deviation

P

UE power with TPC = 0

Time = 21 milliseconds November 2012 | LTE measurements|

78

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

Power

FDD test patterns

0 5 sub-frame#

0

5

TDD test patterns

0

3 8 sub-frame#

3


8

3

79

UE aggregate power tolerance Power

Power

FDD test patterns

0 5 sub-frame#

0

5

TDD test patterns

0

3 8 sub-frame#

3

8

3

Test performed with scheduling gap of 4 subframes November 2012 | LTE measurements|

80

UE power measurement – timing masks Start Sub-frame

Start of ON power

End sub-frame

End of ON power

End of OFF power requirement

Start of OFF power requirement * The OFF power requirements does not apply for DTX and measurement gaps

20µs

20µs

Transient period

Transient period

Timing definition OFF – ON commands

Timing definition ON – OFF commands November 2012 | LTE measurements|

81

Power dynamics

PUSCH = OFF PUSCH = ON PUSCH = OFF Please note: scheduling cadence for power dynamics November 2012 | LTE measurements|

82

time

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


83

PRACH time mask PRACH

ON power requirement End of OFF power requirement

Start of OFF power requirement

20µs

20µs

Transient period

PRACH preamble format

Measurement period (ms)

0

0.9031

1

1.4844

2

1.8031

3

2.2844

4

0.1479

Transient period

Channel bandwidth / Output Power [dBm] / measurement bandwidth

1.4 MHz

3.0 MHz

Transmit OFF power

5 MHz

10 MHz

15 MHz

20 MHz

 -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


84

UE power measurement – PRACH timing mask PRACH preamble format

Measurement period (ms)

0

0.9031

1

1.4844

2

1.8031

3

2.2844

4

0.1479

PRACH

ON power requirement End of OFF power requirement


20µs

20µs

Transient period


Transient period

85

PRACH measurements

For PRACH you have to set a trigger

Reminder: PRACH is CAZAC sequence November 2012 | LTE measurements|

86

PRACH measurement: constellation diagram

Reminder: PRACH is CAZAC sequence


87

PRACH measurement: power dynamics


88

Sounding Reference Signal Time Mask


89

UE power measurement – SRS timing mask SRS SRS ON power requirement

Single Sounding Reference Symbol End of OFF power requirement


20µs

20µs

Transient period

SRS

Double Sounding Reference Symbol

Transient period

SRS

SRS ON power requirement

SRS ON power requirement

End of OFF power requirement 20µs

Transient period

Start of OFF power requirement 20µs

20µs

*Transient period

20µs

Transient period

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


90

UE power measurement – Subframe / slot boundary N+1 Sub-frame

N0 Sub-frame

Sloti Start of N+1 power requirement

20µs

20µs

Transient period

N+2 Sub-frame

Sloti+1 End of N+1 power requirement

20µs

20µs

20µs

Transient period

Transient period

If intra-slot hopping is enabled Periods where power changes may occur November 2012 | LTE measurements|

20µs

91

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


92

Resource allocation versus time PUCCH allocation

No resource scheduled PUSCH allocation, different #RB and RB offset November 2012 | LTE measurements|

93

TTI based scheduling


94

LTE scheduling impact on power versus time

TTI based scheduling. Different RB allocation Impact on UE power


95

Transmit signal quality


96

Transmit signal quality – carrier leakage

Frequency error

fc

f

Fc+ε

Carrier leakage (The IQ origin offset) is an additive sinusoid waveform that has the same frequency as the modulated waveform carrier frequency. Parameters

Relative Limit (dBc)

Output power >0 dBm

-25

-30 dBm ≤ Output power ≤0 dBm

-20

-40 dBm  Output power < -30 dBm

-10


97

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)


98

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 LO leakage level

RF carrier

signal

I/Q imbalance

noise

RB0

RB1

RB2

RB3

RB4

EVM


99

RB5

frequency

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

Used allocation < ½ channel bandwidth

channel bandwidth November 2012 | LTE measurements|

100

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


101

Inband emmission – error cases


102

DC carrier leakage due to IQ offset

Inband emmission – error cases Inband image due to IQ inbalance


103

Inband emmission – error cases Inband image due to IQ inbalance


104

DC leakage and IQ imbalance in real world …


105

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


106

Error Vector Magnitude, EVM Q Magnitude Error (IQ error magnitude)

Error Vector Measured Signal Ideal (Reference) Signal

Φ

Phase Error (IQ error phase)

I Reference Waveform Demodulator

011001…

Ideal Modulator

-

Input Signal

Σ

Difference Signal

+ Measured Waveform November 2012 | LTE measurements|

107

Error Vector Magnitude, EVM 7 symbols / slot time

0123456 0123456 0123456 0123456

PUSCH symbol frequency

Demodulation Reference symbol, DMRS

Limit values Unit

Level

QPSK

%

17.5

16QAM

%

12.5

64QAM

%

[tbd]

Parameter


108

Error Vector Magnitude, EVM CP center

1 SC-FDMA symbol, including Cyclic Prefix, CP OFDM Symbol Part equal to CP

Cyclic prefix FFT Window size FFT window size depends on channel bandwidth and extended/normal CP length


109

Error Vector Magnitude, EVM CP center

1 SC-FDMA symbol, including Cyclic Prefix, CP OFDM Symbol Part equal to CP

Cyclic prefix FFT Window size

FFT window size depends on channel bandwidth and extended/normal CP length Cyclic prefix length

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

128

9

[5]

[55.6]

3

256

18

[12]

[66.7]

512

36

[32]

[88.9]

10

1024

72

[66]

[91.7]

15

1536

108

[102]

[94.4]

20

2048

144

[136]

[94.4]

Channel Bandwidt h MHz

N cp for symbol 0

N cp for symbols 1 to 6

5 160

144

* Note: These percentages are informative and apply to symbols 1 through 6. Symbol 0 has a longer CP and therefore a lower percentage.

Table from TS 36.101 for normal CP November 2012 | LTE measurements|

110

FFT window does not capture the full length: OFDM Symbol + CP

EVM measurement according to Spec Test Parameters for Channel Bandwidths Downlink Uplink Configuration Configuration Ch BW N/A for PUSCH EVM Mod’n RB allocation testing 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 50 (Note 3) (Note 3) 10MHz 16QAM 12 12 15MHz QPSK 75 75 15MHz QPSK 16 16 15MHz 16QAM 75 75 (Note 3) (Note 3) 15MHz 16QAM 16 16 20MHz QPSK 100 100 20MHz QPSK 18 18 20MHz 16QAM 100 100 (Note 3) (Note 3) 20MHz 16QAM 18 18 Note 1: Test Channel Bandwidths are checked separately for each EUTRA 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. November 2012 | LTE measurements| 111 Note 3: Applies only for UE-Categories 2-5

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

* 20MHz, we can only reach 13 dBm

Cyclic prefix aspects We can observe a phase shift

CP part

CP

OFDM symbol n-1 Content is different in each OFDM symbol

CP part

CP

OFDM symbol n OFDM symbol is periodic! Cyclic prefix does not provoque phase shift November 2012 | LTE measurements|

112

Time windowing 1 SC-FDMA symbol, including Cyclic Prefix, CP

1 SC-FDMA symbol, including Cyclic Prefix, CP

Cyclic prefix

OFDM Symbol Cyclic Part equal prefix to CP

OFDM Symbol Part equal to CP

Continuous phase shift Difference in phase shift

Phase shift between SC-FDMA symbols will cause side lobes in spectrum display!


113

Time windowing

Tx time window creates some kind of clipping in symbol transitions

Tx Time window

Tx Time window Cyclic prefix



Continuous phase shift

Difference in phase shift

Tx time window can be used to shape the Tx spectrum in a more steep way, but ….


114

Time windowing

Tx time window creates some kind of clipping in symbol transitions

Tx Time window

Tx Time window Cyclic prefix



Continuous phase shift

Difference in phase shift

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


115

EVM vs. subcarrier Nominal subcarriers Each subcarrier Modulated with e.g. QPSK

f f0

f1

f2

f3 Error vector

....

Error vector

Note: simplified figure: in reality you compare the waveforms due to SC-FDMA November 2012 | LTE measurements|

116

Integration of all Error Vectors to Display EVM curve

EVM vs. subcarrier


117

EVM Equalizer Spectrum Flatness 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. Nominal subcarriers

Amplitude Equalizer coefficients

f f0

f1

Integration of all amplitude equalizer coefficients to display spectral flatness curve

f2

f3

Subcarriers before equalization

1 | A( EC ( f )) |2  12 * N RB 12* N RB P( f )  10 * log | A( EC ( f ) |2 November 2012 | LTE measurements|

118

Equalization 1-tap equalization = Interpreting the frequency Selectivity as scalar factor

Equalizer tries to set same power level for all subcarriers

A(f) 1-tap equalization = Calculating scalar to amplify or attenuate

f


119

Spectrum flatness calculation 1-tap equalization = Interpreting the frequency Selectivity as scalar factor

Equalizer tries to set same power level for all subcarriers

A(f) 1 | A( EC ( f )) |2  12 * N RB 12* N RB P( f )  10 * log | A( EC ( f ) |2

1-tap equalization = Calculating scalar to amplify or attenuate

f


120

Spectral flatness


121

Spectrum Flatness Maximum Ripple [dB] Frequency Range FUL_Meas – FUL_Low ≥ 3 MHz and FUL_High – FUL_Meas ≥ 3 MHz 5.4 (p-p) (Range 1) FUL_Meas – FUL_Low < 3 MHz or FUL_High – FUL_Meas < 3 MHz 9.4 (p-p) (Range 2) 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

< 5.4(5.4) dBp-p

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

max(Range 1)-min(Range 2) < 6.4(7.4) dB

Range 1

Range 2

FUL_High – 3(5) MHz


FUL_High

122

Output RF Spectrum Emissions Out-of-band emissions

occupied bandwidth

Spurious Emissions

Spectrum Emission Mask – SEM -> measurement point by point (RBW) Adjacent Channel Leakage Ratio – ACLR -> integration (channel bandwidth) Spurious domain

ΔfOOB

Channel bandwidth

ΔfOOB

Spurious domain

RB

E-UTRA Band

Worst case: Resource Blocks allocated at channel edge

Harmonics, parasitic emissions, intermodulation and frequency conversion

from modulation process


123

Impact on SEM definition l l

SEM defined for worst case scenario: RBs allocated at channel edge OOB emission scales with channel BW >> a SEM per channel BW configuration

5 MHz QPSK LTE Tx spectrum : +23.0 dBm / +22.0 dBm 30

20

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

10

level (dBm/100kHz)

0

-10

-20

-30

-40

Channel bandwidth 1.4 BWChannel [MHz] Length of OOB domain on one 5 side [MHz]

-50

-60 -10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

1

2

3

4

offset (MHz)


124

3

5

10

15 20

6

10

15

20 25

Adjacent Channel Leakage Ratio - ACLR 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).

l l l

UTRA ACLR 1+2 EUTRA ACLR EUTRA measured with rectangular filter, WCDMA measured with RRC filter ΔfOOB

E-UTRA channel Channel

E-UTRAACLR1

UTRA ACLR2

UTRAACLR1

RB


125

Adjacent Channel Leakage Ratio, ACLR Active LTE carrier, 20MHz BW

1 adjacent LTE carrier, 20MHz BW

2 adjacent WCDMA carriers, 5MHz BW


126

Occupied Bandwidth - OBW Occupied bandwidth is defined as the bandwidth containing 99 % of the total integrated mean power of the transmitted spectrum

99% of mean power

Channel Bandwidth [MHz] Transmission Bandwidth Configuration [RB]

Channel edge

Resource block

Channel edge

Transmission Bandwidth [RB]

Active Resource Blocks

DC carrier (downlink only)


127

Spectrum Emission Mask, SEM OBW: Occupied bandwidth, defined as 99% of mean power SEM: Spectrum ‚Emission Mask, measured with different resolution bandwidth, 1 MHz or 30 kHz RBW

99% of mean power

1 MHz RBW 30 kHz RBW


128

Impact on SEM limit definition Limits depend on channel bandwidth Spectrum emission limit (dBm)/ Channel bandwidth

Limits vary dependent on offset from assigned BW

ΔfOOB (MHz)

1.4 MH z

3.0 M Hz

5 M Hz

10 M Hz

15 M Hz

20 M Hz


 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

-25

-13

-13

-13

-13

1 MHz

-25

-13

-13

-13

1 MHz

-25

-13

-13

1 MHz

-25

-13

1 MHz

-25

1 MHz

 5-6  6-10

 10-15  15-20  20-25


129

SEM definition depends on band Spectrum emission mask depends on additionally signalled band values NS_0x Spectrum emission limit (dBm)/ Channel bandwidth ΔfOOB (MHz)

1.4 MHz

3.0 MHz

5 MHz

10 MHz


 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

-25

-13

-13

1 MHz

-25

-13

1 MHz

-25

1 MHz

 5-6

 6-10  10-15

e.g. NS_07 =band 13


130

Transmitter Spurious Emissions …to verify that UE transmitter does not cause unacceptable interference to other channels or other systems in terms of transmitter spurious emissions. The spurious emission limits apply for the frequency ranges that are more than ΔfOOB (MHz) from the edge of the channel bandwidth

Frequency Range

Maximum Level


9 kHz  f < 150 kHz

-36 dBm

1 kHz

Channel bandwidth

1.4 MHz

3.0 MHz

5 MHz

10 MHz

15 MHz

20 MHz

150 kHz  f < 30 MHz

-36 dBm

10 kHz

30 MHz  f < 1000 MHz

-36 dBm

100 kHz

ΔfOOB (MHz)

2.8

6

10

15

20

25

1 GHz  f < 12.75 GHz

-30 dBm

1 MHz

Spurious domain

ΔfOOB

Channel bandwidth

ΔfOOB

Spurious domain

RB

E-UTRA Band November 2012 | LTE measurements|

131

LTE Uplink: PUCCH Allocation of PUCCH only.

frequency


132

PUCCH measurements PUCCH is transmitted on the 2 side parts of the channel bandwidth


133

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) Interference Signal Frequency Offset

5MHz 5MHz

10MHz

10MHz 10MHz

15MHz

20MHz

Interference CW Signal Level

15MHz

20MHz

30MHz

20MHz

40MHz

-35dBc

-29dBc

-35dBc

18MHz

18MHz

-40dBc

Intermodulation Product

-29dBc

-35dBc

-29dBc

-35dBc


4.5MHz

4.5MHz

9.0MHz

9.0MHz


-29dBc

13.5MHz 13.5MHz

134

Spurious Emissions The spurious emissions power is the power of emissions generated or amplified in a receiver that appear at the UE antenna connector.

General receiver spurious emission requirements Frequency Band 30MHz  f < 1GHz 1GHz  f  12.75 GHz


Maximum level

100 kHz

-57 dBm

1 MHz

-47 dBm


135

SEM – effect of scrambling Scrambling

Modulation mapper

Transform precoder

Resource element mapper

SC-FDMA signal gen.

Constant Bit pattern

Scrambling disabled + constant bit stream

Scrambling should randomize the bit stream


136

LTE Receiver Measurements 1 2 3 4 4.1 4.2 4.3 5 6 6.1 7

Reference sensitivity level Maximum input level Adjacent Channel Selectivity (ACS) Blocking characteristics In-band blocking Out-of-band blocking Narrow band blocking Spurious response Intermodulation characteristics Wide band Intermodulation Spurious emissions


137

LTE open loop power control and RSRP reporting Pathloss =

System Information: referenceSignalPower [-60 .. 50]dBm

referenceSignalPower - RSRP

UE measures RSRP: Reference Signal Receive Power

PDSCH, PUCCH or SRS receive power at eNodeB UE reports RSRP: back to the eNB


UE PDSCH, PUCCH or SRS transmit power at UE

138

Reference Signal Receive Power, RSRP R

R

Entire bandwidth

R

R

Scan over entire bandwidth, RSRP = power of 1 symbol, as mean power


139

Received Signal Strength Indicator, RSSI

noise

R

R

Entire bandwidth

interferer R

R


140

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 cochannel serving and non-serving cells, adjacent channel interference, thermal noise etc.

Applicable for

TBD


141

LTE measurements: RSRQ Reference Signal Received Quality RSRQ =

RSRP RSSI

Definition

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


142

RX Measurements – general setup AWGN Blockers Adjacent channels

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 Use both Rx Antennas

+ Receive feedback on PUSCH or PUCCH

ACK/NACK/DTX Counting

requirements in terms of throughput (BLER) instead of BER November 2012 | LTE measurements|

143

Downlink channel power for Rx tests Physical Channel PBCH

EPRE Ratio

Physical Channel

PBCH_RA = 0 dB

PBCH_RA = A

PBCH

PBCH_RB = 0 dB PSS

PSS_RA = 0 dB

SSS

SSS_RA = 0 dB

PCFICH

PCFICH_RB = 0 dB

PDCCH

PDCCH_RA = 0 dB

PBCH_RB = B

PDCCH_RB = 0 dB PDSCH

PSS

PSS_RA = A

SSS

SSS_RA = A

PCFICH

PCFICH_RB = B

PDCCH

PDCCH_RA = A PDCCH_RB = B

PDSCH_RA = 0 dB PDSCH PDSCH_RB = 0 dB

PHICH

PDSCH_RA = A

PDSCH_RB = B PHICH

PHICH_RB = 0 dB

For tests where no Ref. Signal boosting is applied

EPRE Ratio

PHICH_RB = B

For tests where Ref. Signal boosting is applied, e.g. ρA = -3dB


144

Fixed reference channels Parameter

Unit

Channel bandwidth

MHz

Value 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

QPSK

QPSK

QPSK

QPSK

QPSK

QPSK

1/3

1/3

1/3

1/3

1/3

1/3

8

8

8

8

8

8

1

1

1

1

1

1

Bits

24

24

24

24

24

24

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

kbps

341.6

1143.2

1952.8

3952.8

6040.8

7884

1-5

1-5

1-5

1-5

1-5

1-5

Modulation Target Coding Rate Number of HARQ Processes

Processes

Maximum number of HARQ transmissions

Transport block CRC Number of Code Blocks per Sub-Frame (Note 4)

Max. Throughput averaged over 1 frame UE Category

Fixed reference channels defined in TS 36.101 for receiver quality measurements November 2012 | LTE measurements|

145

RX sensitivity level Criterion: throughput shall be > 95% of possible maximum (depend on RMC) 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)

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

6

-

-

-100

-97

FDD FDD Extract from TS 36.521

Sensitivity depends on band, channel bandwidth and RMC under test November 2012 | LTE measurements|

Duplex Mode

146

Block Error Ratio and Throughput Rx quality

DL signal

Channel setup

Criterion: throughput shall be > 95% of possible maximum (depending on RMC)


147

Details LTE FDD signaling Rx Measurements

l

Rx Measurements l

Counting – ACKnowledgement (ACK) – NonACKnowledgement (NACK) – DTX (no answer from UE)

l

Calculating l

l


148

BLER (NACK/ALL) Throughput [kbps]

Rx measurements: BLER definition PDCCH, scheduling info

Count #NACKs and calculate BLER

PDSCH, as PRBS

ACK/NACK feedback

Assumption is that eNB Power = UE Rx power


149

Rx measurements: BLER definition PDCCH, scheduling info

PDSCH, user data

•ACK = UE properly Receives PDCCH + PDSCH •NACK = UE properly receives PDCCH but does not understand PDSCH •DTX = UE does not understand PDCCH

ACK/NACK feedback

ACK relative = NACK relative = DTX relativ =

# ACK # ACK  # NACK  # DTX

BLER =

# NACK # ACK  # NACK  # DTX

# DTX # ACK  # NACK  # DTX November 2012 | LTE measurements|

150

# NACK  # DTX # ACK  # NACK  # DTX

BLER verification Downlink error insertion to verify the UE reports


151

Transportation Block Size Index Transportation block size User data

TBS Idx

FEC

Modulation

0 QPSK

9

Flexible ratio between data and FEC = adaptive coding

16-QAM 15 64-QAM 26

Data rate No change in data rate, but in reliability

S/N November 2012 | LTE measurements|

152

Throughput versus SNR


153

UE sensitivity – maximum input level

Maximum input level

Rx Parameter

Units

Channel bandwidth 1.4 MHz

Wanted signal mean power

3

MHz

5 MHz

dBm


-25

154

10 MHz

15 MHz

20 MHz

UE sensitivity – RF sensitivity measurement ACK/NACK PRBS 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)

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


155

Duplex Mode

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

Requirement per BW, LTE interferer [1.4MHz]

5MHz

[3MHz]

Padj

ACS= 33dB

ACS= 33dB

Padj = -57.5

Pown= -88.5 Nt= -90.5

Pown= -84.5 Nt= -86.5

2dB IM 1.4MHz LTE 1.4MHz LTE

Pown= -82.3 Nt= -84.3

2dB IM

2dB IM

5MHz LTE

3MHz LTE 3MHz LTE

1.4MHz

3MHz

10MHz

5MHz LTE

5MHz

20MHz

15MHz

= -48.3

Pown= -79.3 Nt= -81.3

Padj

Pown= -77.5 Nt= -79.5

2dB IM

10MHz LTE

5MHz LTE 7.5MHz

Padj,w cdma= -51.3

= -49.5

ACS= 27dB

ACS= 30dB

ACS= 33dB

Padj

= -51.3

= -53.5

ACS= 33dB

Padj

Pow n= -76.3 Nt= -78.3

2dB IM

15MHz LTE

5MHz LTE

20MHz LTE

5MHz LTE 12.5MHz

10MHz


2dB IM

156

Adjacent Channel selectivity 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

Channel bandwidth

Rx Parameter

Units

1.4 MHz

3 MHz

5 MHz

ACS

dB

33.0

33.0

33.0

Rx Parameter

Units

33.0

30

20 MHz 27

Channel bandwidth

1.4 MHz Wanted signal mean power

10 MHz 15 MHz

3 MHz

5 MHz

10 MHz

15 MHz

20 MHz

dBm REFSENS + 14 dB dBm

REFSENS +45.5d B

REFSENS +45.5 dB

REFSENS +45.5dB*

REFSENS +45.5d B

REFSENS +42.5d B

REFSENS +39.5dB

BW Interferer

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

PInterferer


157

Receiver performance - Blocking tests In-band blocking Out-of-band blocking Narrow band blocking

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

CW interferer at a frequency, which is less than the nominal channel spacing

Throughput shall be ≥ 95%

f >> system bandwidth

 fB




fc

158

frequency

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

max 24, 6  N RB / 6

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

N RB

max 8, ( N RB  2  LCRBs ) / 8 exceptions are allowed for spurious response frequencies in each assigned frequency channel when measured using a 1MHz step size, where

N RB

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

Units

E-UTRA band PInterferer 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 2, 5, 12, 17

FInterferer (CW)

FInterferer

dBm

Frequency range 1

range 2

range 3

range 4

-44

-30

-15

-15

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

-

-

-

-

FUL_low - FUL_high

MHz

MHz

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


159

Rx quality - Intermodulation Wanted Signal C

Throughput shall be ≥ 95%

Unmodulated Interferer Icw

f

f

Modulated Interferer Imod

fc

fcw

fmod

See TS 36.101 for power and frequency offset definitions


160

frequency

CQI reporting ≡CQIn+1

Throughput

Overrated CQI report

high

≡CQIn+2

Optimum throughput if the UE reports CQIn

≡CQIn ≡CQIn-1 ≡CQIn-2

Underrated CQI report low

Prevailing conditions of SIR low

SIR changes, CQI reporting must follow!

SIR


161

high

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%


162

Rx tests – test mode UE

SS ACTIVATE TEST MODE

Test modes defined to perform Rx measurements, loop back possible in test mode

ACTIVATE TEST MODE COMPLETE

UE

SS CLOSE UE TEST LOOP

CLOSE UE TEST LOOP COMPLETE


163

UTRAN stack: 2 loop back mode defined Loop back above PDCP, i.e. Layer 2 Packet Data Convergence Protocol PDCP Radio Link Control RLC

Medium Access Control MAC

PHYSICAL LAYER November 2012 | LTE measurements|

164

Test loop mode A UE Test Loop Mode A Function

u0,u u01,u .......u 1 .......u K .................u K -1 N -1

u0,u 1 .......uK -1

User data

User data

Down link

Uplink

UE Test Loop Mode A Function

u0 .. uK -1 ..uN-1 User data

u0...uN -1

u0...uN -1

u0..uK-1

User data

Down link

Uplink November 2012 | LTE measurements|

165

Uplink and downlink may have various capacity

Test loop mode B Loop back above PDCP, i.e. Layer 2

Packet Data Convergence Protocol PDCP PDU size must match

buffer ΔΤ

Delayed loop back November 2012 | LTE measurements|

166

Throughput measurements

Max throughput possible in SISO


167

Rx measurements - throughput Throughput Measurement, Settings for max throughput for SISO:

Number of Resource blocks Modulation scheme Transport block size


168

LTE Downlink BLER and throughput

Rx quality, Indicating NACKs when Lowering the RS EPRE Of the serving cell.


169

Throughput + CQI in LTE Change of RF condition> lower data rate

UE sends different CQI values


170

MIMO testing For MIMO, enable cell

One antenna

eNode B Correlation

ReNB  1

Two antennas

ReNB

1    



 1 

Four antennas

ReNB


1 4    1  9  9   1 4   19 *  1  9  9  4 * 1 * 1   9  9 1  9  * * 4 1  *  9  9 1    

171

MIMO correlation Models from TS 36.521

MIMO in LTE: BLER and throughput


172

Throughput measurements

MIMO active, 2 streams with different data rate


173

Why do we need fading? l

3GPP specifies various tests under conditions of fading l l l l

WCDMA performance tests HSDPA performance tests LTE performance tests LTE reporting of channel state information tests

See CMW capability lists for details l

Evaluation of MIMO performance gain requires fading l l l

Correlated transmission paths in MIMO connection Simulation of “real life conditions” in the lab Comparison of processing gain for different transmission modes


174

Most popular MIMO scheme to increase data rates: Spatial Multiplexing h 11

h 12 TX Ant 1

h22

Space

Matix B

TX Ant 2

d1 LO

d2

h 21

2X2 MIMO

RX Ant 1 RX Ant 2

n1 r1

r2

MIMO RX (e.g. ZF, MMSE,MLD)

Time

n2

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

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.


175

de1

de2

How do we test under conditions of fading?

RF

System simulator

Channel emulator Fading Profile


176

How do we test under conditions of fading?

System simulator I/Q Interface Option CMW-B510x

IQ Out

IQ In

IQ In

IQ Out

RF

Channel emulator Fading Profile November 2012 | LTE measurements|

177

Internal fading in LTE


178

BLER results with and without fading


179

Automatic testing: KT100 LTE + internal fading


180

Measurement sample (open loop SM)


181

BLER vs. SNR Transmit/Receive Diversity

~2dB

AWGN only MCS 7 and 10 Fading EPA 5 Hz Low MCS 7 and 10 ~2dB


182

GUI – IP Settings


183

LTE E2E using DAU


184

LTE E2E using DAU


185

Throughput end to end


186

End to end testing – ping response, RTT


187

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

l

l

IP provides a platform for network convergence enabling a service provider to offer seamless access to any services, How to merge IP anytime, anywhere, and with any device, and cellular 3GPP has taken these developments into account world?? with specification of IMS,

IMS stands for IP Multimedia Subsystem, l

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, Defines an architecture for the convergence of audio, video, data and fixed and mobile networks.


188

3 GPP System Architecture Evolution Signaling interfaces Data transport interfaces RAN Access PDN directly or via IMS MME UE

PDN

Evolved nodeB

S-GW

P-GW

IMS PSTN

Evolved Packet Core

external

IMS to control access + data transfer

All interfaces are packet switched November 2012 | LTE measurements|

189

IMS Architecture


190

IMS protocol structure

user plane

Control plane

SIP/SDP

IKE

Voice video

messaging

RTP

MSRP

UDP / TCP / SCTP IP / IP sec

Layer 3 control

Layer 1/2

Layer 1/2 Mobile com specific protocols

(other IP CAN)

IMS specific protocols


192

IMS protocol structure

Media Transport Quality of Service

Signaling H.323 application layer

transport layer

network layer

link layer

Physical layer

Megaco

SIP

RTSP RSVP RTCP

TCP

Media Encap. e.g. H.261, MPEG

RTP

UDP

IPv4, IPv6 e.g. PPP, AAL2/ATM, AAL5/ATM, MAC Sonet, SDH, PDH, Ethernet, RF link = LTE November 2012 | LTE measurements|

193

ISIM: IMS SIM Security keys

Private user ID

Public user ID

Home network ID

PIN

Administrative data

ISIM = application on UICC USIM for LTE access UICC universal integrated circuit card November 2012 | LTE measurements|

194

IMS Registration and Authentication Comparison with LTE

LTE

IMS

ATTACH REQUEST

REGISTER

AUTHENTICATION REQ

401 UNAUTHORIZED

AUTHENTICATION RSP

REGISTER

ATTACH ACCEPT


200 OK

195

What is IMS?

Registration with IMS l

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). Retrieve S-CSCF First, there was SIM (Subscriber Identity user profile 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 Retrieve S-CSCF capabilities

Calculate RES, REG request SIP registration request P-CSCF

401 User200 notOK authorized November 2012 | LTE measurements|

196

IMS: SMS over IMS

Message flow for a mobile originated SMS

SIP MESSAGE RP-DATA ( SMS-SUBMIT) SIP 200 OK SIP MESSAGE RP-ACK ( SMS-SUBMIT REPORT) SIP 200 OK

SMS Delivery SIP MESSAGE RP-DATA ( SMS-STATUS REPORT) SIP 200 OK SIP MESSAGE RP-ACK SIP 200 OK


197

SMS over IMS

IP based Core Access Network, i.e. EPC

S-CSCF I-CSCF

P-CSCF IP-SM-GW IP short message Gateway to connect S-CSCF to SMS serving centre


198

SMS-SC

HSS

LTE Positioning with SUPL 2.0

LTE radio signal

eNB Measurements based on reference sources*

Target Device

Location Server

LPP Assistance data

SUPL enabled Terminal

UE

LPP over RRC Control plane solution

E-SMLC

SET

LPP over SUPL User plane solution

SLP


199

Enhanced Serving Mobile Location Center

SUPL location platform

Background for IMS and relation to LTE? l

LTE has been designed as a fully packet-orientated, “all-IP”based, multi-service system with a flat network architecture, l

l

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

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. November 2012 | LTE measurements|

200

l

How to connect E-UTRAN to CS services? Connection via IMS: 3GPP and OneVoice initiative

First a big mess, Now it seems to be OneVoice 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


201

IMS: Voice over IMS

Message flow for a mobile originated call INVITE (SDP offer) 183 Session Progress (SDP offer) PRACK 200 OK (PRACK) Resource Reservation

Resource Reservation UPDATE (SDP) 200 OK (UPDATE) (SDP) 180 RINGING PRACK 200 OK (PRACK) 200 OK (INVITE) ACK


202

Voice over IMS: IMS call establishment Originating Home Network

UE

P-CSCF

Terminating Network

S-CSCF

1. Invite (Initial SDP Offer) 2. Invite (Initial SDP Offer) 3. Service Control 4. Invite (Initial SDP Offer) 5. Offer Response 6. Offer Response 7. Authorize QoS Resources 8. Offer Response 9. Response Conf (Opt SDP) 10. Resource Reservation

11. Response Conf (Opt SDP) 12. Response Conf (Opt SDP) 13. Conf Ack (Opt SDP) 14. Conf Ack (Opt SDP)

15. Conf Ack (Opt SDP) 16. Reservation Conf 17. Reservation Conf 18. Reservation Conf 19. Reservation Conf 20. Reservation Conf 21. Reservation Conf 22. Ringing 23. Ringing 24. Ringing 26. 200 OK 25. Alert User

27. 200 OK 28. Enabling of Media Flows

29. 200 OK 30. Start Media 31. ACK 32. ACK 33. ACK


203

Voice over IMS: IMS protocol profile Adaptive Multirate Codecs are used In VoIP over IMS

Codec mode AMR_12.20 AMR_10.20

Source codec bit-rate 12,20 kbit/s (GSM EFR) 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_5.90

5,90 kbit/s

AMR_5.15

5,15 kbit/s

AMR_4.75

4,75 kbit/s

AMR_SID

1,80 kbit/s (see note 1)


204

QoS class identifiers QCI QCI

Priority

Packet Delay Budget

Packet Error Loss Rate

1

2

100 ms

10-2

Conversational Voice

2

4

150 ms

10-3

Conversational Video (Live Streaming)

3

50 ms

10-3

Real Time Gaming

4

5

300 ms

10-6

Non-Conversational Video (Buffered Streaming)

5

1

100 ms

10-6

IMS Signalling

3

Resource Type

GBR

6

6

300 ms

7

7

100 ms

8

8

9

9

10-6

Non-GBR

Example Services

Video (Buffered Streaming) TCP-based (e.g. www, e-mail, chat, ftp, p2p file sharing, progressive video, etc.)

10-3

Voice, Video (Live Streaming), Interactive Gaming

10-6

Video (Buffered Streaming) TCP-based (e.g. www, e-mail, chat, ftp, p2p file sharing, progressive video, etc.)

300 ms


205

Voice over LTE – protocol profiles AMR codec

Optimize transmission of Voice by configuring Lower layers 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

UDP/ TCP IP Packet Data Convergence PDCP Radio Link Control RLC

Medium Access Control MAC

PHYSICAL LAYER


206

IMS: Voice over IMS Interaction with EPS l

Resource reservation (QoS) can be achieved with separate Radio Bearers

SIP QCI = 5 signalling

Voice QCI GBR DRB

QCI = 1

NonGBR

GBR

Default Bearer

Dedicated Bearer

AM DRB

PDCP RLC MAC PHY

UM DRB

Quality of Service Class Indicator Guaranteed Bitrate Data Radio Bearer


207

VoLTE connection to CS via IMS CS Connection via Boarder and Media Gateway of IMS Control plane IP based Core Access Network, i.e. EPC

S-CSCF I-CSCF

How to connect VoLTE To legacy network? PSTN CS network

P-CSCF BGW MGCF

BGCF

User plane

MG November 2012 | LTE measurements|

208

HSS

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?


209

Radio Access Technologies today CDMA2K 1xEVDO

GERAN UTRAN

EUTRAN LTE coverage is not fully up from day one -> interworking with legacy networks is essential!!! November 2012 | LTE measurements|

210

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


211

2G or 3G CS fallback Voice call E-UTRAN

MME

IMS

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


212

2G or 3G CS fallback CS connection as fallback to legacy networks

UE

SGSN GERAN

Voice calls are routed via 2G or 3G

UTRAN MSC

E-UTRAN

MME

Only for signalling

Only packet switched connections


213

CSFB issues and questions UTRAN

Target cell assigned or selected by UE? Uu

Iu-ps

SGSN

Gs

Gb GERAN S3

Um

UE

LTE Uu

Iu-cs

MSC Server

A

E-UTRAN

S1-MME

SGs MME

Handover or Redirection?

•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? November 2012 | LTE measurements|

214

CS fallback options to UTRAN and GERAN Feature group index, UE indicates CSFB support


215

CS fallback to 1xRTT 1xCS CSFB UE

1xRTT CS Access

1xRTT MSC

A1 A1

Tunneling of messages between 1xRTT MSC and UE

1xCS IWS S102 MME

S1-MME 1xCS CSFB UE

S11 Serving/PDN GW

E-UTRAN S1-U

Tunnelled 1xRTT messages


216

S102 is the reference point between MME and 1xCS interworking solution SGi

CS fallback to 1xRTT


217

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


218

Why not CSFB? 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


219

Dual receiver 1xCSFB UE

Circuit switched 1xRTT registration CDMA2000 cell eNB for LTE 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! November 2012 | LTE measurements|

220

SV-LTE: Simultaneous CDMA200 + LTE

UE

Circuit switched 1xRTT connection CDMA2000 cell eNB for LTE Packet switched EUTRAN connection

Simultaneous Voice UEs can handle 2 radio links at the same time. UE is registered to MME and CDMA2K independently


221

OTT – over the top

EUTRAN

Application UE

Evolved nodeB

S-GW

P-GW

PDN

Evolved Packet Core Voice call as application, e.g. Skype, Google talk, … November 2012 | LTE measurements|

222

OTT – over the top - arguments EUTRAN

UE

Application Evolved nodeB

S-GW

P-GW

PDN

Evolved Packet Core

•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 November 2012 | LTE measurements|

223

SMS transfer in LTE Encapsulate SMS in NAS Control message-> SMS over SG EMM

Send SMS over IMS Using IP protocol SMS over IMS ESM

User plane

Radio Resource Control RRC

Control & Measurements

Packet Data Convergence PDCP

Radio Bearer

Radio Link Control RLC Logical channels Medium Access Control MAC

Transport channels PHYSICAL LAYER


224

CSFB circuit switched fallback – SMS transfer Iu-ps UTRAN

SMS-SC

SGSN

Gs Gb Uu

GERAN S3

Um

MSC Server

A

LTE-Uu UE

Iu-cs

SGs

S1-MME E-UTRAN

For 1xRTT it is the S102 interface

MME

SMS transfer between SMS-SC and MME via new interface SGs. New protocol SGs interface application protocol November 2012 | LTE measurements|

SGsAP

SGsAP

SCTP

SCTP

IP

IP

L2

L2

L1

L1

MME

225

SGs

MSC Server

CSFB circuit switched fallback – SMS transfer SGs interface MS/UE

eNodeB

MME

MSC/VLR

HLR/HSS

1. EPS/IMSI attach procedure

SMS-SMS GMSC

SC

2. Message transfer 3. Send Routeing Info For Short Message

5. Paging 7. Paging

4. Forward Short Message

6. Paging

8. Service Request 9b. Downlink NAS Transport 9c. Uplink NAS Transport 10. Uplink NAS Transport

8a. Service Request

No real fallback, because SMS is sent over NAS signaling

9a. Downlink Unitdata 9d. Uplink Unitdata 11. Uplink Unitdata 12. Delivery report

15. Downlink NAS Transport

13. Delivery report

14. Downlink Unitdata 16. Release Request

Mobile terminated SMS in idle mode, SMS over SG November 2012 | LTE measurements|

226

CSFB circuit switched fallback – SMS transfer 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 November 2012 | LTE measurements|

227

Single Radio Voice Call Continuity Problem: in first network roll-out, there is no full LTE coverage. How to keep call active? => SRVCC


228

SRVCC – Single Radio Voice Call Continuity SGSN GERAN

UE

Handover of voice call to 2G or 3G

UTRAN MSC

E-UTRAN

MME

User plane after handover User plane before handover November 2012 | LTE measurements|

IMS

SRVCC is handover from EUTRAN to 2G/3G if no LTE coverage 229

Single Radio Voice Call Continuity UE

E-UTRAN

MME

MSC Server

Target UTRAN/GERAN

Measurement Reports Handover to UTRAN/GERAN required

Initiates SRVCC for voice component Handles PS-PS HO for non-voice if needed

Handover CMD

To eUTRAN Coordinates SRVCC and PS HO response

CS handover preparation IMS Service Continuity Procedure

PS HO response to MME (CS resources)

Handover execution


230

3GPP IMS

Single Radio Voice Call Continuity VoLTE call

eNodeB = EUTRAN Handover to UTRAN

VoIP in PS mode

NodeB = UTRAN

Radio Bearer reconfiguration: PS to CS mode time

NodeB = UTRAN

Voice call in CS mode


231

l

Handover requirements l

Goal is to have seamless service continuity between LTE and other Legacy Technologies (CDMA2000, WCDMA, GSM)

Data and Voice services l l l l l

Support of all frequency bands and a single radio solution Transparent signaling to allow an independent protocol evolution for both access systems Impact to QoS, e.g. service interruption, should be minimized RAT change procedure shall limit interruption time to less than 300ms 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


232

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.)


233

Handover – what to discuss? UE reads SysInfo

GERAN cell(s)?

eNodeB EUTRAN cell

UTRAN cell(s)? CDMA2K cell(s)? UE Will the UE initiate the change? -> re-selection Will the network initiate the change? -> redirection or handover

NW sends Redirection command? SysInfo of Target?

Handover command?


Mandatory for UE supporting CSFB

234

Handover aspects – what to discuss? l

Some keywords that appear – and to be clarified in next slides:

l

Handover? Cell reselection? Cell change order? Redirection? Network assisted cell change, NACC? Circuit switched fallback, CS fallback?

l

l l l l


235

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. in idle – B.

Support of measurements and cell reselection procedure mode Support of RRC release with redirection procedure in

connected – C.

mode

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 November 2012 | LTE measurements|

236

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 EUTRA 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 November 2012 | LTE measurements|

237

LTE Radio Resource Control States 1. What about mobility, when UE is in IDLE state?

Cell search and selection de-allocate Tracking Area ID (TA-ID) and IP address and system information acquisition LTE random access procedure [Initial Access; allocate C-RNTI, TA-ID, IP address]

release of C-RNTI, allocate DRX cycle for PCH

LTE_DETACHED • No IP address assigned, • UE location unknown.

Power-up

LTE_ACTIVE (RRC_CONNECTED) • IP address assigned, • Connected to known cell. OUT_OF_SYNCH

IN_SYNCH

• DL reception possible, • No UL transmission.

• DL reception possible, • UL transmission possible.

© Rohde&Schwarz, 2010

LTE/eHRPD-capable terminal

• IP address assigned, • UE position partially known.

LTE random access procedure [Transition to LTE_ACTIVE state (IN_SYNCH)]

LTE random access procedure [to restore uplink synchronization]

User Equipment (UE)

LTE_IDLE (RRC_IDLE)

2. What about mobility, when UE is in CONNECTED state?


238

Mobility between LTE and WCDMA/GSM Radio Access Aspects

GSM_Connected CELL_DCH

Handover

E-UTRA RRC_CONNECTED

Handover GPRS Packet transfer mode

CELL_FACH

CELL_PCH URA_PCH

CCO with optional NACC Reselection Connection establishment/release

Connection establishment/release UTRA_Idle

CCO, Reselection

Reselection

E-UTRA RRC_IDLE

Connection establishment/release

Reselection CCO, Reselection


239

GSM_Idle/GPRS Packet_Idle

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


240

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

EUTRAN

RRCConnectionRelease


241

Redirection to UMTS UE reads SysInfo

eNodeB EUTRAN cell

NodeB(s) UTRAN cell(s) UE will search for suitable cell on UARFCN and initiate CS connection

UE

RRC connection release message with RedirectedCarrierInfo to UTRAN Mandatory for UE supporting CSFB

RRC connection release with redirection without SysInfo November 2012 | LTE measurements|

242

Redirection to UMTS

Rel. 9 feature

UE reads SysInfo

NodeB UTRAN cell

UE will go to indicated cell and initiate CS connection

Sys Info UE

eNodeB EUTRAN cell

RRC connection release message with RedirectedCarrierInfo to UTRAN e-RedirectionUTRA capability is set by UE

RRC connection release with redirection with SysInfo November 2012 | LTE measurements|

243

Redirection to GERAN

eNodeB EUTRAN cell

BTS(s) GSM cell(s) UE will search for suitable cell on ARFCN and initiate CS connection

UE

RRC connection release message with RedirectedCarrierInfo to GSM Mandatory for UE supporting CSFB


244

Redirection to GERAN

Rel. 9 feature

BTS(s) GSM cell(s) UE will go to indicated cell and initiate CS connection

Sys Info UE

eNodeB EUTRAN cell

RRC connection release message with RedirectedCarrierInfo to GSM e-RedirectionUTRA capability is set by UE

RRC connection release with redirection with SysInfo November 2012 | LTE measurements|

245

IRAT Procedures PS Handover l

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

l

NW sends handover command e.g. l

l

l

LTE → WCDMA: MobilityFrom EUTRACommand WCDMA → LTE: HandoverFromUTRANCommand_EUTRA

PS radio bearer is immediately setup on target RAT


246

Handover (Intra-LTE) AS-security has been activated, and SRB2 with at least one DRB are setup UE

EUTRAN

RRCConnectionReconfiguration

RRCConnectionReconfigurationComplete


247

Packet Switched handover to other RAN UE

EUTRAN

MobilityFromEUTRACommand

Contains this information element when Falling back to legacy networks 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 {} } }


248

Handover (Intra-MME/Serving Gateway) UE

Target eNB

Source eNB

MME

Measurement reporting Handover decision Handover request Admission Control

Handover request Ack RRC connection reconfiguration 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


249

Handover to UMTS: Packet switched handover

eNodeB EUTRAN cell

NodeB(s) UTRAN cell(s) UE UE will select target cell on UARFCN and continue PS connection

MobilityFromEUTRACommand message with purpose indicator = handover to UTRAN EUTRAN contains targetRATmessagecontainer, = Inter-RAT info about target cell

Packet Switched handover to UTRAN November 2012 | LTE measurements|

250

HandoverfromEUTRAN – target RAT message HandoverFromEUTRAN message contains control message of target RAT. Possible messages are: targetRAT-Type geran

Standard to apply

targetRAT-MessageContainer

GSM TS 04.18, or 3GPP TS 44.018

HANDOVER COMMAND

3GPP TS 44.060

PS HANDOVER COMMAND

3GPP TS 44.060

DTM HANDOVER COMMAND

cdma20001XRTT

C.S0001 or later, C.S0007 or later, C.S0008 or later

cdma2000HRPD

C.S0024 or later

utra

3GPP TS 25.331


HANDOVER TO UTRAN COMMAND 251

Mobility from EUTRAN – failure case UE

EUTRAN


RRC connection re-establishment

Radio link failure in target RAT

UE will try to Reestablish EUTRAN connection


252

UE mobility in LTE (RRC CONNECTED state)

Measurement configuration, related RRC messages & information elements RRCConnectionReconfiguration … MeasConfig ...

MeasConfig MeasObjectToAddModList ReportConfigToAddMod QuantityConfig measGapConfig

MeasObjectToAddModList

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…

… MeasObjectCDMA2000

How? What? When?

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)

ReportConfigToAddMod … ReportConfigInterRAT

measGapConfig Each gap starts at SFN & subframe meeting these conditions : SFN mod T = FLOOR(gapOffset/10) with T = MGRP/10 Subframe = gapOffset mod 10

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

When to retune the receiver to measure e.g. CDMA2000 or HRPD…


253

Inter-RAT Handover to GERAN: cell change order PS connection will be suspended

eNodeB EUTRAN cell

BTS(s) GPRS cell(s) UE will search for suitable cell on ARFCN and re-initiate PS connection

UE

MobilityFromEUTRACommand message with purpose indicator = Cell Change Order to GPRS Mandatory for UE supporting CSFB

Packet Switched cell change order to GPRS without NACC (network assisted cell change) November 2012 | LTE measurements|

254

Inter-RAT Handover to GERAN: cell change order PS connection will be suspended

BTS GPRS cell UE will search for suitable cell on ARFCN and initiate PS connection

Sys Info UE

eNodeB EUTRAN cell

MobilityFromEUTRACommand message with purpose indicator = Cell Change Order to GPRS Mandatory for UE supporting CSFB

Packet Switched cell change order to GPRS with NACC (network assisted cell change) November 2012 | LTE measurements|

255

Inter-RAT Handover to GERAN: handover PS connection will be handed over

eNodeB EUTRAN cell

BTS GPRS cell UE will search for suitable cell on ARFCN and continue PS connection

UE

MobilityFromEUTRACommand message with purpose indicator = handover to GPRS Mandatory for UE supporting CSFB

Packet Switched handover to GPRS November 2012 | LTE measurements|

256

LTE-RTT Handover Circuit Switched Fallback, CSFB

Overview November 2012 | LTE measurements|

257

3GPP Changes l

LTE Broadcast Channel l l

l l

l

Tunneling l

l

CDMA System Time 1xEVDO, 1xRTT, WCDMA, GSM cell parameters Cell (re)selection parameters Broadcast as SIB Type 8 or via Dedicated RRC messages

Receiving 1xEVDO overhead messages with dual Rx ATs

Measurement Gaps


258

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 l l l

l

Non-optimized and optimized handoff from LTE to eHRPD Preamble Initial Power for handover complete message Handover to 1xEV-DO Rev. B being considered Circuit-Switched Fallback (CS fallback) currently specified in C.S0097-0

Core network changes l

l l

S101 interface – signaling interface S103 interface – bearer interface PDSN extension (now called HSGW) November 2012 | LTE measurements|

259

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


260

CS fallback to 1xRTT 1xCS CSFB UE

1xRTT CS Access

1xRTT MSC

A1 A1

Tunneling of messages between 1xRTT MSC and UE

1xCS IWS S102 MME

S1-MME 1xCS CSFB UE

S11 Serving/PDN GW

E-UTRAN S1-U

Tunnelled 1xRTT messages


261

S102 is the reference point between MME and 1xCS interworking solution SGi

CS fallback to 1xRTT


262

CS fallback to 1xRTT CSFB to 1xRTT

MME

CSFB Info

eNodeB EUTRAN cell

1xRTT cell(s)

UE will search for suitable cell on UARFCN and initiate CS connection

UE

RRC connection release message with RedirectedCarrierInfo to Mandatory 1xRTT for UE

Enhancement: UE can pre-register in 1xRTT network

supporting CSFB to 1xRTT


263

CS fallback to 1xRTT UE

E-UTRAN

MME

1xCS IWS

1xRTT MSC

UE is EPS attached and registered with 1xRTT CS

UE decision to perform MO call in 1xCS

EXTENDED SERVICE REQUEST (with service type CSFB)

UE CONTEXT MODIFICATION REQUEST (CS Fallback Indicator)

UE CONTEXT MODIFICATION RESPONSE

Optional measurement reports

RRCConnectionRelease with redirection to 1xRTT

UE CONTEXT RELEASE REQUEST Suspend Notification Suspend Acknowledge

UE context release

MO call establishment in 1xRTT network


264

S-GW/ P-GW

CS fallback to 1xRTT enhanced 1xCSFB (e1xCSFB) Enhancement: UE can pre-register in 1xRTT network UE

1) Prepare for handover, search for 1xRTT

EUTRAN

HandoverFromEUTRAPreparationRequest

UE

2) Info about 1xRTT -> tunnelled via S102

EUTRAN

ULHandoverPreparationTransfer

UE

3) Includes 1xRTT channel assignment

EUTRAN



265

Time flow

CS fallback to 1xRTT enhanced 1xCSFB (e1xCSFB) + concurrent HRPD handover Enhancement: UE can pre-register in 1xRTT network

1) Prepare for handover, search for 1xRTT + HRPD

UE

EUTRAN

HandoverFromEUTRAPreparationRequest

2) Trigger 2 messages with info about 1xRTT + HRPD

UE

EUTRAN


UE

EUTRAN


UE

3) Redirection to 1xRTT and handover to HRPD

EUTRAN



266

Time flow

LTE-eHRPD Handover Overview


267

InterRAT Network Architecture Eg CDMA2000 1xEVDO


268

EUTRAN – eHRPD non-roaming

i.e. US subscriber, connected To home network, leaves LTE coverage area November 2012 | LTE measurements|

269

EUTRAN – eHRPD, roaming case

i.e. European subscriber visiting US, connected to roaming network and leaving LTE coverage area November 2012 | LTE measurements| 270

Mobility between LTE and HRPD Radio Access Aspects

No handover to EUTRAN

HRPD active to EUTRAN is always cell reselection (via RRC idle) November 2012 | LTE measurements|

272

3 Step Procedure E-UTRAN needs to decide, that HO to HRPD is required

Ability of preregistration is indicated on PBCCH

UE attached to E-UTRAN

Pre-registration

HO preparation

HO execution

• Reduces time for cell re-selection or handover • Reduces risk of radio link failure Traffic Channel Assignment command is delivered to UE, re-tune radio to HRPD channel, acquire HRPD channel, session configuration

Connection Request issued by UE to HRPD, HRPD prepares for the arrival of the UE


273

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

Introduction l

Cisco quote 06/2011 l

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 exchanged 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.

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. November 2012 | LTE measurements|

278

Introduction Network view

Impact due to EPC / IMS

l Packet delay

l Packet jitter l Packet loss MME

PCRF

l …

Node B SGW

Impact due to

PGW

Internet

l Multipath propagation l Speed l …

Node B


279

Introduction

Testing real life conditions in the lab l

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

Exploring the performance of mobile equipment from the end user perspective Measuring E2E throughput with realistic radio conditions Evaluating mobility performance R&S®AMU200 baseband fader simulates real life radio conditions

R&S®CMW500 emulates LTE network

l

CMW-PQA

Important aspect for end user perspective: Error free video reception November 2012 | LTE measurements|

280

Contest SW provides automation and reporting capabilities

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

l

Subjective quality assessment Objective quality assessment


281

Video transmission over LTE

The video processing chain and possible sources for video degradation • Encoding artifacts (blocking)

Impairments on the transmission link can cause loss of information despite active error correction

• Video / audio delay • Buffer rules are violated

The decoder is usually the less critical component. But in conjunction with the video processor, errors during the conversion process (e.g. deinterlacing) are possible

Transmission link (IP, cellular, broadcast, etc.) Encoder

TX

RX

Decoder

Receiver

Uncompressed video SDI SMPTE249/292/424

Video processor

Redundant information (static image parts) and irrelevant data (details) is omitted

Restoring the video Scaling and information; i.e. the conversion to output picture sequence format including redundant data


282

Output on screen

Video transmission over LTE Subjective quality assessment l

Subjective video quality assessments are defined in ITU-T recommendation BT.500 Mean Opinion Score (MOS)

l

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).

Advantages: l

l

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

Disadvantages: l l

Time consuming and expensive Automation not possible


283

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 l l

l

Advantage: l

l

Full reference methods (FR) Reduced reference methods (RR) No-reference methods (NR)

Assessment automation is possible for various applications

Disadvantages: l l

Correlation with the actual perceived video quality is not always ensured Many different metrics for specific purposes exist


284


Objective metric – peak signal-to-noise ratio (PSNR) MAX I2 PSNR  10  log10 ( ) MSE 1 m 1 n 1 I (i, j )  K (i, j )2 MSE    mn i 0 j 0

l

Most commonly used for quality measurements for image compression.

l

Simple mathematical calculation but poor correlation with subjective methods: l

I(i,j) = original pixel

l

K(i,j) = reconstructed pixel MAX = maximum possible pixel value

l

Digital pixel values do not exactly represent the light stimulus on the human eye The summation is averaging errors without weighting them The same PSNR values may result from different kind of structural errors

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


285


Objective metric – structural similarity (SSIM) Signal x

Luminance Measurement

+ Signal y

Contrast Measurement

Luminance Comparison

÷ Luminance Measurement

+ SSIM ( x, y ) 

Contrast Measurement

Contrast Comparison

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.

Similarity Measure Combination

Structure Comparison

÷ (2 x  y  C1 )(2 xy  C2 )

(  x2   y2  C1 )( x2   y2  C2 )

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

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.


286


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.


287

Video transmission over LTE Metric – visible error l

The shown objective metrics and their correlation with MOS are calculated frame based Temporal masking effects need to be considered: l

Additional condition: e.g. for at least 6 frames SSIM below 0.7 (25 fps video) 1,2 1 0,8 Not visible

SSIM

l

Not visible

0,6

Visible 1 Visible 2

0,4 0,2 6 Frames

Visible Error

0 1

3

5

7

9

11

13

15

17

19

Frame


288

21

23

Video transmission over LTE Demo


289

Video transmission over LTE Testing real life conditions in the lab

PC Contest TC Control

RF

Video via MHL or HDMI


290

Video transmission over LTE R&S®VTE Video Tester l

l

l l

l l

Source, sink and dongle testing on MHL 1.2 interfaces and in the future also HDMI 1.4c, etc. Realtime difference picture analysis for testing video transmissions over LTE Combined protocol testing and audio/video analysis Future-ready, modular platform accommodating up to three test modules Localized touchscreen user interface Integrated test automation and report generation


R&S®VTE Video Tester

291

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 l

l

Single-wire Control Bus (CBUS) l l l

l

Configuration and status exchange Replaces the DDC bus in HDMI Carries the MHL Sideband Channel (MSC) which provides high level control functions

VBUS and associated ground l l


Carries video, audio and auxiliary data Bit stream is modulated by a clock signal

Provide power between sink and source 5V, max. 0.5 A 292

Summary l l

Video and voice are important services gaining momentum for the fastest developing radio access technology ever - LTE 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


293

There will be enough topics for future trainings



Thank you for your attention! Comments and questions welcome! November 2012 | LTE measurements|

294

LTE measurements.pdf

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