LTE Measurement: How to test a device

LTE, UMTS Long Term Evolution

LTE measurements – from RF to
application testing
Reiner Stuhlfauth
Reiner.Stuhlfauth@rohde-schwarz.com

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 -
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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


LTE: EPS Bearer

E-UTRAN EPC Internet

UE eNB S-GW P-GW Peer
Entity

End-to-end Service

EPS Bearer External Bearer

Radio Bearer S1 Bearer S5/S8 Bearer

Radio S1 S5/S8 Gi


Mobile Radio Testing
Adjust the downlink Generate downlink
signal to how uplink is Perform
signal and send control
received RF measurements on
commands
received uplink

Core network

A mobile radio tester emulates a
base station


Mobile Radio Testing
Generate downlink Generate downlink
signal and send signal
signaling information No signaling Control PC

Signaling testing Non-Signaling testing


LTE measurements
general aspects


LTE RF Testing Aspects
UE requirements according to 3GPP TS 36.521
Power Transmit signal quality
 Maximum output power Frequency error
 Maximum power reduction Modulation quality, EVM
 Additional Maximum Power Carrier Leakage
Reduction In-Band Emission for non allocated RB
 Minimum output power
EVM equalizer spectrum flatness
 Configured Output Power
Output RF spectrum emissions
 Power Control
 Occupied bandwidth
 Absolution Power Control
 Out of band emissions
 Relative Power Control
 Aggregate Power Control  Spectrum emisssion mask

 ON/OFF Power time mask  Additional Spectrum emission mask
 Adjacent Channel Leakage Ratio
36.521: User Equipment (UE) radio
transmission and reception Transmit Intermodulation


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


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


BS requirements according to 3GPP, cont.

l Receiver Characteristics
l Reference sensitivity level
l Dynamic range
l Adjacent Channel Selectivity (ACS)
l Blocking characteristics
l Intermodulation characteristics
l Spurious emissions
l Performance


LTE RF Measurements – regional requirements

l Regional / band-specific requirements exist (e.g. spurious emissions)
l Since UEs roam implementation has to be dynamic

 Concept of network signaled RF requirements has been introduced with
LTE.
- Network signaled value: NS_01 … NS_32
- transmitted as IE AdditionalSpectrumEmission in SIB2


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

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

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

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

4 Yes Yes Yes Yes Yes Yes

5 Yes Yes Yes Yes[1]

6 Yes Yes[1]



9 Yes Yes Yes[1] Yes[1]

10 Yes Yes Yes Yes

11 Yes Yes[1]

12 Yes Yes Yes[1] Yes[1]

13

14
Yes[1]

Yes[1]
Yes[1]

Yes[1]
Not every channel
...

17 Yes[1] Yes[1]
bandwidth for
... every band!
33 Yes Yes Yes Yes

34 Yes Yes Yes



37 Yes Yes Yes Yes

38 Yes Yes Yes Yes

39 Yes Yes Yes Yes

40 Yes Yes Yes Yes

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


Tests performed at “low, mid and highest frequency”
Nominal frequency
RF power

described by EARFCN
(E-UTRA Absolute lowest EARFCN possible
Radio Frequency
Channel Number)
and 1 RB at position 0

Frequency = whole LTE band
RF power

mid EARFCN
and 1 RB at position 0

Frequency
RF power

Highest EARFCN
and 1 RB at max position

Frequency


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 Minimum Requirement in TS Test Test Requirement in TS 36.521-
36.101 Tolerance 1
(TT)
6.2.2. UE Power class 1: [FFS] 0.7 dB Formula:
Maximum Output Power class 2: [FFS] 0.7 dB Upper limit + TT, Lower limit - TT
Power Power class 3: 23dBm ±2 dB 0.7 dB Power class 1: [FFS]
Power class 4: [FFS] 0.7 dB Power class 2: [FFS]
Power class 3: 23dBm ±2.7 dB
Power class 4: [FFS]


LTE RF measurements
on base stations


OFDM risk: Degradation

Channel (ideal)

sl  n  rl  n 

1
TMC

Samples
f
f0 f1 f2 f3 f0 f1 f2 f3

OFDM risk: Degradation due to Frequency Offset

Channel
e j 2fn

sl  n  rl  n 

f

Samples
f
f0 f1 f2 f3 f0 f1 f2 f3


OFDM risk: Degradation due to Clock Offset

Channel

sl  n   rl  n 

f  k

Samples
f
f0 f1 f2 f3 f0 f1 f2 f3


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

Downlink:
f-1 f+1
1
j 2kf t  N CP ,l Ts 
N RB Nsc / 2
DL RB

sl( p ) t    ak (p)) ,l  e
(
  ak( (p)) ,l  e j 2kf t  NCP ,lTs  DC subcarrier,

k   N RB N sc / 2
DL RB
 k 1 suppressed
1/TSYMBOL=15kHz
Uplink:
N RB Nsc / 2 1
UL RB

j 2 k 1 2 f t  N CP ,l Ts 
sl t    a k (  ) ,l  e

k   N RB N sc / 2
UL RB
 f-1 f0 f1
f
½ subcarrier
DC subcarrier
offset

LTE: DC subcarrier usage

DC subcarrier or subcarrier 0 is not used in downlink!


DC offset – possible reasons
DC offset originated by mixer:

fBB=fRx-fLO
fRX=fLO+fBB+fLO_ɛ 1st mixer
fLO –fLO_ɛ=DC fBB + DC

Non-linearities of
fLO_ɛ fLO 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!

Base station test models
Parameter 1.4 MHz 3 MHz 5 MHz 10 MHz 15 MHz 20 MHz
Reference, Synchronisation Signals
RS boosting, PB = EB/EA 1 1 1 1 1 1
Synchronisation signal EPRE / ERS [dB] 0.000 0.000 0.000 0.000 0.000 0.000
Reserved EPRE / ERS [dB] -inf -inf -inf -inf -inf -inf
PBCH
PBCH EPRE / ERS [dB] 0.000 0.000 0.000 0.000 0.000 0.000
Reserved EPRE / ERS [dB] -inf -inf -inf -inf -inf -inf
PCFICH
# of symbols used for control channels 2 1 1 1 1 1
PCFICH EPRE / ERS [dB] 3.222 0 0 0 0 0
PHICH
# of PHICH groups 1 1 1 2 2 3
# of PHICH per group 2 2 2 2 2 2
PHICH BPSK symbol power / ERS [dB] -3.010 -3.010 -3.010 -3.010 -3.010 -3.010
PHICH group EPRE / ERS [dB] 0 0 0 0 0 0
PDCCH
# of available REGs 23 23 43 90 140 187
# of PDCCH 2 2 2 5 7 10
# of CCEs per PDCCH 1 1 2 2 2 2 TS 36.141
# of REGs per CCE 9 9 9 9 9 9
# of REGs allocated to PDCCH 18 18 36 90 126 180
Defines several
# of <NIL> REGs added for padding 5 5 7 0 14 7 Test models
PDCCH REG EPRE / ERS [dB] 0.792 2.290 1.880 1.065 1.488 1.195
<NIL> REG EPRE / ERS [dB] -inf -inf -inf -inf -inf -inf For base station
PDSCH
# of QPSK PDSCH PRBs which are boosted 6 15 25 50 75 100
e.g. E-TM1.1
PRB PA = EA/ERS [dB] 0 0 0 0 0 0
# of QPSK PDSCH PRBs which are de-boosted 0 0 0 0 0 0

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


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

RB

E-UTRA Band

Worst case:
Ressource Blocks allocated
at channel edge

Adjacent Channel Leakage Ratio - eNB
E-UTRA transmitted BS adjacent channel Assumed Filter on the ACLR
signal channel centre adjacent adjacent lim
bandwidth frequency offset channel channel it
BWChannel [MHz] below the first carrier frequency and
or above the last (informative) corresponding
carrier centre filter bandwidth
frequency
transmitted
1.4, 3.0, 5, 10, 15, 20 BWChannel E-UTRA of same Square (BWConfig) 45 dB
BW

2 x BWChannel E-UTRA of same Square (BWConfig) 45 dB
BW

BWChannel /2 + 2.5 3.84 Mcps UTRA RRC (3.84 Mcps) 45 dB
MHz
BWChannel /2 + 7.5 3.84 Mcps UTRA RRC (3.84 Mcps) 45 dB
MHz
NOTE 1: BWChannel and BWConfig are the channel bandwidth and transmission bandwidth configuration
of the E-UTRA transmitted signal on the assigned channel frequency. Large bandwidth
NOTE 2: The RRC filter shall be equivalent to the transmit pulse shape filter defined in TS 25.104 [6],
with a chip rate as defined in this table.
Limit is either -13 / -15dBm absolute or as above

Adjacent channel leakage power ratio


ACLR measurement * RBW 10 kHz
VBW 30 kHz
Ref 0 dBm Att 25 dB SWT 250 ms

0
*
A
-10

1 AP
VIEW
-20

2 AP
VIEW
-30

3 AP
CLRWR
-40

-50 EXT
UTRAACLR1 UTRAACLR2
= 33 dB = 36 dB UTRAACLR2bis
3DB
= 43 dB
-60

-70

-80

-90 Additional requirement for
E-UTRA frequency band I,
-100 signaled by network to the UE
Center 1.947 GHz 2.5 MHz/ Span 25 MHz

fUTRA, ACLR2 fUTRA, ACLR1 fCarrier

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

Operating band unwanted emissions
Narrow bandwidth
Frequency offset Frequency offset of Minimum requirement Measurem
of measurement measurement filter centre ent
filter -3dB point, f frequency, f_offset bandwidth
(Note 1)

0 MHz  f < 5 0.05 MHz  f_offset < 5.05 100 kHz
7  f _ offset 
MHz MHz  7dBm     0.05 dB
5  MHz 
5 MHz  f < 5.05 MHz  f_offset < -14 dBm 100 kHz
min(10 MHz, min(10.05 MHz,
fmax) f_offsetmax)

10 MHz  f  10.05 MHz  f_offset < -16 dBm (Note 5) 100 kHz
fmax f_offsetmax

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!

Operating band unwanted emissions


Unwanted emissions – spurious emission
The transmitter spurious emission limits apply from 9 kHz to 12.75 GHz,
excluding the frequency range from 10 MHz below the lowest frequency of the downlink
operating band up to 10 MHz above the highest frequency of the downlink operating band

Frequency range Maximum level Measurement Note
Bandwidth

9kHz - 150kHz 1 kHz Note 1

150kHz - 30MHz 10 kHz Note 1

-13 dBm
30MHz - 1GHz 100 kHz Note 1

1GHz – 12.75 GHz 1 MHz Note 2

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

Spurious emission limits, Category A


Spurious emissions – operating band excluded


Base station maximum power
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.
Towards
External External antenna connector
PA device 
BS e.g.
cabinet TX filter
(if any) (if any)

Test port A Test port B

Normal port for Port to be used for
measurements measurements in case
external equipment is
used

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


Base station receiver test
Example: Rx test, moving condition

70% of required throughput of FRC, Fixed Reference Channel


Base station receiver test – HARQ multiplexing

UE sends PUSCH with alternating data
and data with multiplexed ACK


Base station test – power dynamics

Synchronisation
time/frequency

BS under
Test FFT
2048
Per Symbol
100 subcarrier Detection /
RF- CP- RBs, Ampl. decoding
correc- remov 1200 /Phase
tion sub correction
carr

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


Downlink Power
Reference Signal:
Cell-specific PDCCH power
PDSCH power to RS, where NO reference
referenceSignalPower depending
signals are present, is UE specific and
(-60…+50dBm), on ρB/ρA
signaled by higher layers as PA.
signaled in SIB Type 2
For PDSCH power in same
[Power] symbol as reference signal an
additional cell specific offset
is applied, that is signaled by
-50.00 dBm higher layers as PB.

PA = -4.77 dB

2011 © Rohde&Schwarz
-54.77 dBm

PB = 3 (-3.98 dB)

-58.75 dBm

0 1 2 3 4 5 6 7 8 9 10 11 12 13 [Time]
OFDM symbols

RS EPRE = Reference Signal Reference signal power = linear average of all Ref.
Energy per Resource Element Symbols over whole channel bandwidth

EPRE PDSCH   A / B  EPRE RS B  PB   A  A  PA (with some exeptions for MIMO)


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 1 1 1 1 1 Test model:
PRB PA = EA/ERS [dB] 0 0 0 0 0 0 E-TM3.1
# of PDSCH PRBs which are not allocated 5 14 24 49 74 99
All RB allocated

Test model: PDSCH
# of 64QAM PDSCH PRBs within a slot for which EVM 6 15 25 50 75 100
E-TM2 is measured
Only 1 RB allocated


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

PDSCH with
16 QAM
PDCCH +
PBCH with
QPSK
S-SCH with
BPSK
CAZAC
Sequences,
Reference signals


LTE RF measurements
on user equipment UEs


LTE Transmitter Measurements
1 Transmit power
1.1 UE Maximum Output Power
1.2 Maximum Power Reduction (MPR)
1.3 Additional Maximum Power Reduction (A-MPR)
1.4 Configured UE transmitted Output Power
2 Output Power Dynamics
2.1 Minimum Output Power
2.2 Transmit OFF power
2.3 ON/OFF time mask
2.3.1 General ON/OFF time mask
2.3.2 PRACH time mask
2.3.3 SRS time mask
2.4 Power Control
2.4.1 Power Control Absolute power tolerance
2.4.2 Power Control Relative power tolerance
2.4.3 Aggregate power control tolerance
3 Transmit signal quality
3.1 Frequency Error
3.2 Transmit modulation
3.2.1 Error Vector Magnitude (EVM)
3.2.2 Carrier leakage
3.2.3 In-band emissions for non allocated RB
3.2.4 EVM equalizer spectrum flatness
4 Output RF spectrum emissions
4.1 Occupied bandwidth
4.2 Out of band emission
4.2.1 Spectrum Emission Mask
4.2.2 Additional Spectrum Emission Mask
4.2.3 Adjacent Channel Leakage power Ratio
4.3 Spurious emissions
4.3.1 Transmitter Spurious emissions
4.3.2 Spurious emission band UE co-existence
4.3.3 Additional spurious emissions
5 Transmit intermodulation


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

…
…
…
equalizer IDFT meas.
DUT RF
correction FFT
Inband-

…
…
…
emmissions

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


UL Power Control: Overview
UL-Power Control is a
combination of:

l Open-loop:
UE estimates the DL-Path-
loss and compensates it
for the UL

l Closed-loop:
in addition, the eNB
controls directly the UL-
Power through power-
control commands
transmitted on the DL


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

Maximum allowed UE power
in this particular cell, Combination of cell- and UE-specific PUSCH transport
but at maximum +23 dBm1) components configured by L3 format

Number of allocated Cell-specific Downlink Power control
resource blocks (RB) parameter path loss adjustment derived
Transmit power for PUSCH configured by L3 estimate from TPC command
in subframe i in dBm received in subframe (i-4)

Bandwidth factor Basic open-loop starting point Dynamic offset (closed loop)
1) +23 dBm is maximum allowed power in LTE according to TS 36.101, corresponding to power class 3bis in WCDMA


Pcmax definition „upper“ tolerance
„lower“ 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 Max. power
in cell, permitted in cell
considering bandwidth
confinement Max. power for
UE
Max. power for UE,
considering maximum
power reduction


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
PPowerClass - 2dB
-1.5dB -1.5dB

FUL_low FUL_high- 4MHz 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 Network may signal
= 23dBm ±2 dB bandwidth restriction
NS_0x


UE Maximum Power Reduction
UE transmits
at maximum power, maximum allowed
TX power reduction is given as

Modulation Channel bandwidth / Transmission bandwidth configuration MPR (dB)
[RB]
1.4 3.0 5 10 15 20
MHz MHz MHz MHz MHz MHz
QPSK >5 >4 >8 > 12 > 16 > 18 ≤1
16 QAM ≤5 ≤4 ≤8 ≤ 12 ≤ 16 ≤ 18 ≤1
16 QAM Full >5 >4 >8 > 12 > 16 > 18 ≤2

Higher order modulation schemes require
more dynamic -> UE will slightly repeal its
confinement for maximum power

UE Additional Maximum Power Reduction A-MPR
Additional maximum Network Requirements E-UTRA Band Channel Resource A-MPR (dB)
Signaling (sub-clause) Bandwidth Blocks
power reduction value (MHz)
requirements can be NS_01 NA NA NA NA NA
signaled by the 6.6.2.2.3.1 2,4,35,36 3 >5 ≤1
network as NS value 6.6.2.2.3.1 2,4,10,35,36 5 >6 ≤1
in SIB2 NS_03 6.6.2.2.3.1 2,4,10,35,36 10 >6 ≤1
(IE AdditionalSpectrumEmission) 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

6.6.2.2.3.3 Table
NS_07 13 10 Table 6.2.4.3-2
6.6.3.3.3.2 6.2.4.3-2
> 29 ≤1
NS_08 6.6.3.3.3.3 19 10, 15 > 39 ≤2
> 44 ≤3
[NS_09] 6.6.3.3.3.4 21 TBD TBD TBD

..

NS_32 - - - - -


PUSCH power control
Transmit output power ( PUMAX), cont’d.
3GPP Band 13
746 756 777 787

DL UL

Network Requiremen Channel
E-UTRA Resources A-MPR
Signalling ts bandwidth
Band Blocks (dB)
Value (sub-clause) (MHz)
… … … … … …
Table Table
6.6.2.2.3
NS_07 13 10 6.2.4 6.2.4
6.6.3.3.2
-2 -2
Indicates the lowest RB
… … … … … …
index of transmitted
Region A Region B Region C
resource blocks

RBStart 0 – 12 13 – 18 19 – 42 43 – 49
Defines the length of a
contiguous RB allocation LCRB [RBs] 6–8 1 – 5 to 9 – 50 ≥8 ≥18 ≤2

A-MPR [dB] 8 12 12 6 3

l In case of EUTRA Band 13 depending on RB allocation as well as
number of contiguously allocated RB different A-MPR needs to be
considered. November 2012 | LTE measurements| 50

Pcmax definition – tolerance values

PCMAx Tolerance
(dBm) T(PCMAX) (dB)
21 ≤ PCMAX ≤ 23 2.0
Tolerance is 20 ≤ PCMAX < 21 2.5
depending on
19 ≤ PCMAX < 20 3.5
power levels
18 ≤ PCMAX < 19 4.0
13 ≤ PCMAX < 18 5.0
8 ≤ PCMAX < 13 6.0
-40 ≤ PCMAX < 8 7.0



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



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,

Class 1 Tolerance Class 2 Tolerance Class 3 Tolerance (dB) Class 4 Tolerance (dB)
EUTRA
(dB (dB) (dBm) (dB) (dBm (dBm)
band m) )

1 23 ±2
2 23 ±22
… 23 ±22
40 23 ±2


Pcmax value for power control - analogies


Maximum speed = 280 km/h
=PPowerClass

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


LTE RF Testing: UE Maximum Power

UE transmits
with 23dBm ±2 dB

QPSK modulation is used. All channel bandwidths are
tested separately. Max power is for all band classes
Test is performed for varios uplink allocations


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

band width One active resource block
10 MHz
= 50 RB’s
(RB) provides maximum
absolute RF power

Frequency
More RB’s in use will be at
RF power

lower RF power in order to
create same integrated
power
Frequency
RF power

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

Frequency


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 Temperature/Voltage
Test Frequencies as specified in TS 36.508 subclause 4.3.1 Low range, Mid range, High range high/low

Test Channel Bandwidths as specified in TS 36.508 subclause 4.3.1 Lowest, 5MHz, Highest
Test Parameters for Channel Bandwidths
Downlink Configuration Uplink Configuration
Ch BW N/A for Max UE output power testing Mod’n RB allocation
FDD TDD
1.4MHz QPSK 1 1
1.4MHz QPSK 5 5
3MHz QPSK 1 1
3MHz QPSK 4 4
5MHz QPSK 1 1
5MHz QPSK 8 8
10MHz QPSK 1 1
10MHz QPSK 12 12
15MHz QPSK 1 1
15MHz QPSK 16 16
20MHz QPSK 1 1
20MHz QPSK 18 18


UE maximum power
PPowerClass + 2dB

23dBm
PPowerClass - 2dB

maximum output FUL_high
FUL_low power for any
transmission bandwidth
within the channel bandwidth


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

23dBm
PPowerClass - 2dB
-1.5dB -1.5dB

FUL_low FUL_high- 4MHz FUL_high
FUL_low+4MHz
For transmission bandwidths confined within FUL_low and FUL_low + 4 MHz or
FUL_high – 4 MHz and FUL_high, the maximum output power requirement is relaxed
by reducing the lower tolerance limit by 1.5 dB

UE maximum power - examples
Example 1: No maximum power reduction by higher layers


Max. power permitted in cell, Max. power for UE, Max. power permitted in Max. power for UE
considering bandwidth considering maximum power cell
confinement reduction

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

23dBm

PPowerClass - 2dB 21dBm

FUL_low FUL_high


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



PEMAX_L = 0dBm -1.5 dB relaxation = -1.5dBm PEMAX_H = 0 dBm
PUMAX = power class 3 – band relaxation = +21.5 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 -8.5dBm

FUL_low FUL_low+4MHz FUL_high


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

PEMAX_L = none PEMAX_H = none
PUMAX = power class 3 – MPR – A.MPR = +10 dBm PPowerClass = power class 3 = +23 dBm

PCMAX_L=10 dBm T(PCMAX_L) = 6 dB PCMAX_H=23 dBm +25dBm
T(PCMAX_H)=2dB
PCMAX_H +2dB
23 dBm

PCMAX_L - 6dB 4 dBm

RB start = 13 12 Resource blocks FUL_high


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

PEMAX_L =none PEMAX_H = none
PUMAX = power class 3 – MPR-A-MPR-band relaxation PPowerClass = power class 3 = +23 dBm
= 23-1-1-1.5=+19.5 dBm
PCMAX_H= 23 dBm
PCMAX_L=19.5dBm PCMAX_H + 2dB +25 dBm
T(PCMAX_L) = 3.5 dB
T(PCMAX_H)=2dB
23 dBm
PCMAX_L – 2 dB
PCMAX_L – 3.5 dB
+16 dBm

FUL_low FUL_low+4MHz FUL_high


LTE RF Testing: UE Minimum Power

UE transmits
with -40dBm

All channel bandwidths are tested separately.
Minimum power is for all band classes < -39 dBm


LTE RF Testing: UE Off Power

The transmit OFF power is defined as the mean power in a duration of at least one
sub-frame (1ms) excluding any transient periods. The transmit OFF power shall not
exceed the values specified in table below

Channel bandwidth / Minimum output power / measurement bandwidth

1.4 3.0 5 10 15 20

Transmit OFF power -50 dBm

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


Power Control Related test items

l Absolute Power Control Tolerance -- PUSCH open loop
power control

l Relative Power Control Tolerance – PUSCH relative power
control, including both power ramping and power change due
to Ressource block allocation change or TPC commands

l Aggregate Power Control – PUSCH and PUCCH power
control ability when RB changes every subframe


Absolute Power Control Tolerance
l The purpose of this test is to verify the UE transmitter’s
ability to set its initial output power to a specific value at the
start of a contiguous transmission or non-contiguous
transmission with a long transmission gap.


Power Control - Absolute Power Tolerance
l …. ability to set initial output power to a specific value at the start of a
contiguous transmission or non-contiguous transmission with a long
transmission gap (>20ms).

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

l Test requirement example for test point 1:

Channel bandwidth / expected output power (dBm)
1.4 3.0 5 10 15 20
Expected Measured
-14.8 ± -10.8 ± -8.6 ± -5.6 ± -3.9 ± -2.6 ±
power Normal
10.0 10.0 10.0 10.0 10.0 10.0
conditions
Expected Measured
-14.8 ± -10.8 ± -8.6 ± -5.6 ± -3.9 ± -2.6 ±
power Extreme
13.0 13.0 13.0 13.0 13.0 13.0
conditions


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 3.0 5 10 15 20
PCMAX test point 1 -10 dBm ± 7.7
PCMAX test point 2 10 dBm ± 6.7
PCMAX test point 3 15 dBm ± 5.7


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


Accumulative TPC commands

TPC Command Field Accumulated
In DCI format 0/3  PUSCH [dB]
0 -1
1 0
2 1
3 3

2
minimum
power in LTE


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 Absolute  PUSCH [dB]
In DCI format 0/3 only DCI format 0
0 -4
1 -1
2 1
3 4

Pm
-1
-4


Relative Power Control
Power pattern B
Power pattern A

RB change

RB change

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

Power pattern C

l The purpose of this test is to verify
RB change 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
0 ..
1
9 sub-frame#
2 3 4 radio frame transmission gap between these sub-
frames is ≤ 20 ms.

Power Control – Relative Power Tolerance
l …. ability to set output power relative to the power in a target sub
frame, relative to the power of the most recently transmitted
reference sub-frame, if the transmission gap between these
sub-frames is ≤ 20 ms.


Power Control – Relative Power Tolerance
l Various power ramping patterns are defined

ramping down

alternating

ramping up


UE power measurements – relative power change
All combinations of
All combinations of PUSCH/PUCCH
Power step P
PUSCH and and SRS
(Up or down) PRACH [dB]
PUCCH transitions
[dB]
transitions [dB] between sub-
frames [dB]
ΔP < 2 ±2.5 (Note 3) ±3.0 ±2.5
2 ≤ ΔP < 3 ±3.0 ±4.0 ±3.0
3 ≤ ΔP < 4 ±3.5 ±5.0 ±3.5
4 ≤ ΔP ≤ 10 ±4.0 ±6.0 ±4.0
10 ≤ ΔP < 15 ±5.0 ±8.0 ±5.0
15 ≤ ΔP ±6.0 ±9.0 ±6.0
P

Power tolerance relative given by table

time


UE power measurements – relative power change
Power Power

FDD test patterns TDD test patterns
test for
each
bandwidth,
here 10MHz
0 1 9 sub-frame# 0 2 3 7 8 9 sub-frame#

Sub-test Uplink RB allocation TPC command Expected power
Power step size
step size
range (Up or PUSCH/
(Up or
down)
down)
ΔP [dB] ΔP [dB] [dB]
A Fixed = 25 Alternating TPC =
1 ΔP < 2 1 ± (1.7)
+/-1dB
B Alternating 10 and 18 TPC=0dB 2.55 2 ≤ ΔP < 3 2.55 ± (3.7)
C Alternating 10 and 24 TPC=0dB 3.80 3 ≤ ΔP < 4 3.80 ± (42.)
D Alternating 2 and 8 TPC=0dB 6.02 4 ≤ ΔP < 10 6.02 ± (4.7)
E Alternating 1 and 25 TPC=0dB 13.98 10 ≤ ΔP < 15 13.98 ± (5.7)
F Alternating 1 and 50 TPC=0dB 16.99 15 ≤ ΔP 16.99 ± (6.7)


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
P deviation

UE power with
TPC = 0

Time = 21 milliseconds


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


0 5 0 5 0 3 8 3 8 3
sub-frame# sub-frame#


UE aggregate power tolerance

Power Power


0 5 0 5 0 3 8 3 8 3
sub-frame# sub-frame#

Test performed with scheduling gap of 4 subframes


UE power measurement – timing masks

Start Sub-frame End sub-frame

Start of ON power End of ON power

End of OFF power Start of OFF power
requirement 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


Power dynamics

PUSCH = OFF PUSCH = ON PUSCH = OFF time
Please note: scheduling cadence for power dynamics

General ON/OFF time mask
Measured subframe = 2
UL/DL Scheduling should be configured properly.
TDD Issues:
- Special Subframe
Configuration
- >off power before is
highter than off
power after
- <> tune down DL
power


PRACH time mask
PRACH

ON power requirement


20µs 20µs


PRACH Channel bandwidth / Output Power [dBm] / measurement
Measurement bandwidth
preamble
period (ms)
format 1.4 3.0 5 10 15 20
0 0.9031 MHz MHz MHz MHz MHz MHz
Transmit OFF
1 1.4844  -48.5 dBm
power
2 1.8031 Transmission OFF
3 2.2844 Measurement 1.08 MHz 2.7 MHz 4.5 MHz 9.0 MHz 13.5 MHz 18 MHz
bandwidth
4 0.1479
Expected PRACH
Transmission ON -1± 7.5 -1 ± 7.5 -1 ± 7.5 -1 ± 7.5 -1 ± 7.5 -1 ± 7.5
Measured power


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


20µs 20µs



PRACH measurements

For PRACH
you have to
set a trigger Reminder:
PRACH is
CAZAC
sequence


PRACH measurement: constellation diagram

Reminder:
PRACH is
CAZAC
sequence


PRACH measurement: power dynamics


Sounding Reference Signal Time Mask


UE power measurement – SRS timing mask
SRS

SRS ON power
requirement
Single Sounding
Reference Symbol
End of OFF Start of OFF power
power requirement requirement

20µs 20µs


SRS SRS

Double Sounding SRS ON power SRS ON power
Reference Symbol requirement requirement

End of OFF Start of OFF power
power requirement requirement

20µs 20µs 20µs 20µs
Transient period *Transient period Transient period

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


UE power measurement – Subframe / slot boundary

N+1 Sub-frame
N0 Sub-frame N+2 Sub-frame
Sloti Sloti+1

Start of N+1 power End of N+1 power

20µs 20µs 20µs 20µs 20µs 20µs

Transient period Transient period Transient period

If intra-slot hopping is enabled

Periods where power changes may occur


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


Resource allocation versus time

PUCCH
allocation

No resource
scheduled
PUSCH allocation, different #RB and RB offset


TTI based scheduling


LTE scheduling impact on power versus time

TTI based scheduling.
Different RB allocation
Impact
on UE
power


Transmit signal quality


Transmit signal quality – carrier leakage

Frequency error

fc Fc+ε f

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


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

The 20 frequency error Δf results must fulfil this test requirement:
|Δf| ≤ (0.1 PPM + 15 Hz)
observed over a period of one time slot (0.5ms)


Impact on Tx modulation accuracy evaluation
l 3 modulation accuracy requirements
l EVM for the allocated RBs
l LO leakage for the centred RBs ! LO spread on all RBs
l I/Q imbalance in the image RBs
LO leakage
level
RF carrier

signal I/Q imbalance

noise

RB0 RB1 RB2 RB3 RB4 RB5 frequency

EVM


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

Used
allocation <
½ channel
bandwidth

channel bandwidth

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 Parameters Relative
Leakage Limit (dBc)

Output power >0 dBm -25

-30 dBm ≤ Output power ≤0 dBm -20
-40 dBm  Output power < -30 dBm -10


Inband emmission – error cases
DC carrier leakage
due to IQ offset


Inband image
due to IQ inbalance


DC leakage and IQ imbalance in real world …


UL Modulation quality: Constellation diagram
LTE PUSCH uses
QPSK, 16QAM
and 64 QAM (optional)
modulation schemes.
In UL there is only 1 scheme
allowed per subframe


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

Error Vector
Measured
Signal
Ideal (Reference) Signal
Φ
Phase Error (IQ error phase)

I

Reference Waveform
011001… Ideal
Demodulator
Modulator -
Input Signal
Σ Difference Signal
+

Measured Waveform


7 symbols / slot
0123456 0123456 0123456 0123456 time

PUSCH symbol
frequency
Demodulation Reference
symbol, DMRS

Limit values
Unit Level

Parameter
QPSK % 17.5
16QAM % 12.5
64QAM % [tbd]


CP center
1 SC-FDMA symbol, including Cyclic Prefix, CP
OFDM
Cyclic Symbol
prefix Part equal
to CP
FFT Window size

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


CP center
1 SC-FDMA symbol, including Cyclic Prefix, CP
OFDM
Cyclic Symbol
prefix Part equal
to CP
FFT Window size

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

N cp Ratio of
N cp Cyclic prefix EVM
Channel W to CP
for symbols 1 Nominal for symbols window
Bandwidt for symbol 0 for
to 6 FFT size 1 to 6 in FFT length
h MHz symbols 1
samples W
to 6*
FFT window does
1.4 128 9 [5] [55.6]

3 256 18 [12] [66.7]
not capture the
5 512 36 [32] [88.9]
full length: OFDM
10
160 144
1024 72 [66] [91.7] Symbol + CP
15 1536 108 [102] [94.4]

20 2048 144 [136] [94.4]

* Note: These percentages are informative and apply to symbols 1 through 6. Symbol 0 has a
longer CP and therefore a lower percentage.
Table from TS 36.101 for normal CP


EVM measurement according to Spec
Test Parameters for Channel Bandwidths
Downlink Uplink Configuration
l Applies to PUSCH, PUCCH Configuration
Ch BW N/A for PUSCH EVM Mod’n RB allocation
and PRACH 1.4MHz
testing
QPSK
FDD
6
TDD
6
l PUSCH and PUCCH UL Tx 1.4MHz
1.4MHz
QPSK
16QAM
1
6
1
6
1.4MHz 16QAM 1 1
Pwer 3MHz QPSK 15 15

l @ Max & -36.8 dBm
3MHz QPSK 4 4
3MHz 16QAM 15 15
3MHz 16QAM 4 4
l PRACH UL Tx Power 5MHz QPSK 25 25
5MHz QPSK 8 8
l FDD: @ -31 dBm & 14 dBm* 5MHz
5MHz
16QAM
16QAM
25
8
25
8
l TDD: @ -39 dBm & 6 dBm 10MHz
10MHz
QPSK
QPSK
50
12
50
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 E-
* 20MHz, we can only reach 13 dBm UTRA band, which applicable channel bandwidths are specified in Table
5.4.2.1-1.
Note 2: For partial RB allocation, the starting resource block shall be
RB #0 and RB# (max+1 - RB allocation) of the channel bandwidth.
November 2012 | LTE measurements|
Note 3: 111
Applies only for UE-Categories 2-5

Cyclic prefix aspects
We can observe a phase shift

CP CP
CP part CP part

OFDM symbol n-1 OFDM symbol n

Content is OFDM symbol is periodic!
different in each
OFDM symbol Cyclic prefix does not provoque
phase shift


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

OFDM OFDM
Cyclic Symbol Cyclic Symbol
prefix Part equal prefix Part equal
to CP to CP
Continuous phase shift
Difference in phase shift

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


Time windowing Tx time window creates
some kind of clipping in
symbol transitions

Tx Time window Tx Time window
OFDM OFDM
to CP to CP

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


Time windowing Tx time window creates
some kind of clipping in
symbol transitions

Tx Time window Tx Time window
OFDM OFDM
to CP to CP

Tx time window will create
a higher Error Vector Magnitude!

Here the Tx time window of 5µsec causes
Some mismatch between the 2 EVM
Measurements of the first SC-FDMA symbol


EVM vs. subcarrier
Nominal subcarriers

Each subcarrier
Modulated with
e.g. QPSK

Integration of all
f Error Vectors to
Display EVM curve
f0 f1 f2 f3

Error vector

....

Error vector

Note: simplified figure: in reality you
compare the waveforms due to SC-FDMA


EVM vs. subcarrier


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 f2 f3 Subcarriers before
equalization
Integration of all
1
amplitude equalizer
coefficients to display
| A( EC ( f )) |2
12 * N RB 12* N RB
P( f )  10 * log
spectral flatness curve | A( EC ( f ) |2


Equalization
1-tap equalization =
Interpreting the frequency
Selectivity as scalar factor
Equalizer tries to
set same power level for
all subcarriers

A(f)

Calculating scalar to
amplify or attenuate

f


Spectrum flatness calculation
Interpreting the frequency
Equalizer tries to
Selectivity as scalar factor set same power level for
all subcarriers

A(f)

1 1-tap equalization =
| A( EC ( f )) |2
12 * N RB 12* N RB Calculating scalar to
P( f )  10 * log amplify or attenuate
| A( EC ( f ) |2

f


Spectral flatness


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) < 9.4(13.4) dBp-p
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


Output RF Spectrum Emissions
Out-of-band emissions occupied Spurious Emissions
bandwidth
Spectrum Emission Mask – SEM
-> measurement point by point (RBW)

Adjacent Channel Leakage Ratio – ACLR
-> integration (channel bandwidth)
Channel

RB

E-UTRA Band

Worst case: from Harmonics, parasitic
Resource Blocks allocated at modulation emissions, intermodulation
channel edge process and frequency conversion


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

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

30

20

10 1 RB MPR 0dB
5 RBs MPR 0dB
6 RBs MPR 0dB
0 7 RBs MPR 0dB
8 RBs MPR 0dB Channel
level (dBm/100kHz)

9 RBs MPR 1dB bandwidth
-10 10 RBs MPR 1dB 1.4 3 5 10 15 20
11 RBs MPR 1dB
BWChannel
12 RBs MPR 1dB [MHz]
-20 13 RBs MPR 1dB
14 RBs MPR 1dB
Length of OOB
15 RBs MPR 1dB domain on one 5 6 10 15 20 25
-30 16 RBs MPR 1dB
18 RBs MPR 1dB
side [MHz]
20 RBs MPR 1dB
-40 25 RBs MPR 1dB

-50

-60
-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4
offset (MHz)


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 UTRA ACLR 1+2
l EUTRA ACLR
l EUTRA measured with rectangular filter,
WCDMA measured with RRC filter
ΔfOOB E-UTRA channel

Channel

E-UTRAACLR1 UTRA ACLR2 UTRAACLR1

RB


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

1 adjacent LTE
carrier, 20MHz BW

2 adjacent WCDMA
carriers, 5MHz BW


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]

Transmission
Bandwidth [RB]

Channel edge
Channel edge

Resource block

Active Resource Blocks DC carrier (downlink only)


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


Impact on SEM limit definition

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

ΔfOOB 1.4 3.0 5 10 15 20 Measurement
(MHz) MH M M M M M bandwidth
z Hz Hz Hz Hz 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

 5-6 -25 -13 -13 -13 -13 1 MHz
Limits vary
 6-10 -25 -13 -13 -13 1 MHz
dependent on offset
 10-15 -25 -13 -13 1 MHz
from assigned BW
 15-20 -25 -13 1 MHz

 20-25 -25 1 MHz


SEM definition depends on band
Spectrum emission mask depends on additionally signalled band values NS_0x

Spectrum emission limit (dBm)/ Channel bandwidth

ΔfOOB 1.4 3.0 5 10 Measurement
(MHz) MHz MHz MHz MHz bandwidth
 0-0.1 -13 -13 -15 -18 30 kHz
 0.1-1 -13 -13 -13 -13 100 kHz
 1-2.5 -13 -13 -13 -13 1 MHz
 2.5-5 -25 -13 -13 -13 1 MHz
 5-6 -25 -13 -13 1 MHz

 6-10 e.g. -25 -13 1 MHz
NS_07
 10-15 =band 13 -25 1 MHz


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 Frequency Range Maximum Measurement
ranges that are more than ΔfOOB (MHz) from the Level Bandwidth
edge of the channel bandwidth
9 kHz  f < 150 kHz -36 dBm 1 kHz
150 kHz  f < 30 MHz -36 dBm 10 kHz
Channel 1.4 3.0 5 10 15 20
bandwidth MHz MHz MHz MHz MHz MHz 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

Channel

RB

E-UTRA Band


LTE Uplink: PUCCH

Allocation of
PUCCH only.

frequency


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


Transmit intermodulation
The transmit intermodulation performance is a measure of the capability of the transmitter
to inhibit the generation of signals in its non linear elements caused by presence of the
wanted signal and an interfering signal reaching the transmitter via the antenna.

User Equipment(s) transmitting in close vicinity of each other can produce intermodulation products,
which can fall into the UE, or eNode B receive band as an unwanted interfering signal.
The UE intermodulation attenuation is defined by the ratio of the mean power of the wanted signal
to the mean power of the intermodulation product when an interfering CW signal is added at a level
below the wanted signal at each of the transmitter antenna port with the other antenna port(s)
if any is terminated.

BWChannel (UL) 5MHz 10MHz 15MHz 20MHz
Interference Signal
5MHz 10MHz 10MHz 20MHz 15MHz 30MHz 20MHz 40MHz
Frequency Offset
Interference CW Signal
-40dBc
Level
Intermodulation Product -29dBc -35dBc -29dBc -35dBc -29dBc -35dBc -29dBc -35dBc
Measurement bandwidth 4.5MHz 4.5MHz 9.0MHz 9.0MHz 13.5MHz 13.5MHz 18MHz 18MHz


Spurious Emissions
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 Measurement Maximum
Bandwidth level
30MHz  f < 1GHz 100 kHz -57 dBm
1GHz  f  12.75 GHz 1 MHz -47 dBm


SEM – effect of scrambling
Modulation Transform Resource SC-FDMA
Scrambling element mapper
mapper precoder signal gen.
Constant
Bit pattern
Scrambling
disabled +
constant bit
stream
Scrambling
should
randomize the
bit stream


LTE Receiver Measurements

1 Reference sensitivity level
2 Maximum input level
3 Adjacent Channel Selectivity (ACS)
4 Blocking characteristics
4.1 In-band blocking
4.2 Out-of-band blocking
4.3 Narrow band blocking
5 Spurious response
6 Intermodulation characteristics
6.1 Wide band Intermodulation
7 Spurious emissions


LTE open loop power control and RSRP reporting
Pathloss =
System Information:
referenceSignalPower referenceSignalPower - RSRP
[-60 .. 50]dBm

UE measures RSRP:
Reference Signal
Receive Power

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


Reference Signal Receive Power, RSRP

R R
Entire bandwidth

R R

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


Received Signal Strength Indicator, RSSI

R
noise R
Entire bandwidth

interferer
R R


LTE measurements
RSRP = Reference Signal Received Power

Definition Reference signal received power, the mean measured power of the
reference symbols during the measurement period.

Applicable for TBD

E-UTRA Carrier RSSI

Definition E-UTRA Carrier Received Signal Strength Indicator, comprises the total
received wideband power observed by the UE from all sources, including co-
channel serving and non-serving cells, adjacent channel interference, thermal
noise etc.

Applicable for TBD


LTE measurements: RSRQ Reference Signal Received Quality
RSRP
RSRQ =
RSSI

Definition Reference Signal Received Quality (RSRQ) is defined as the ratio N×RSRP/(E-
UTRA carrier RSSI), where N is the number of RB’s of the E-UTRA carrier
RSSI measurement bandwidth. The measurements in the numerator and
denominator shall be made over the same set of resource blocks.
E-UTRA Carrier Received Signal Strength Indicator (RSSI), comprises the
linear average of the total received power (in [W]) observed only in OFDM
symbols containing reference symbols for antenna port 0, in the
measurement bandwidth, over N number of resource blocks by the UE
from all sources, including co-channel serving and non-serving cells,
adjacent channel interference, thermal noise etc.
The reference point for the RSRQ shall be the antenna connector of the UE.
If receiver diversity is in use by the UE, the reported value shall not be lower
than the corresponding RSRQ of any of the individual diversity branches.
Applicable for RRC_CONNECTED intra-frequency,
RRC_CONNECTED inter-frequency


RX Measurements – general setup
AWGN
Receive Sensitivity Tests Blockers
Adjacent channels
Transmit data
User according to
definable table on PDSCH
DL Use both
assignment Rx Antennas
Table
(TTI based)
+

Receive feedback
Specifies DL scheduling
on PUSCH
parameters like
or PUCCH
RB allocation
Modulation, etc.
for every TTI (1ms) ACK/NACK/DTX

Counting

requirements in terms of throughput (BLER) instead of BER

Downlink channel power for Rx tests
Physical Channel EPRE Ratio Physical Channel EPRE Ratio

PBCH PBCH_RA = 0 dB
PBCH PBCH_RA = A
PBCH_RB = 0 dB
PBCH_RB = B
PSS PSS_RA = 0 dB
PSS PSS_RA = A
SSS SSS_RA = 0 dB
SSS SSS_RA = A
PCFICH PCFICH_RB = 0 dB
PCFICH PCFICH_RB =
PDCCH PDCCH_RA = 0 dB
B
PDCCH_RB = 0 dB PDCCH PDCCH_RA = A
PDCCH_RB = B
PDSCH PDSCH_RA = 0 dB
PDSCH PDSCH_RA = A
PDSCH_RB = 0 dB PDSCH_RB = B

PHICH PHICH_RB = 0 dB PHICH PHICH_RB = B

For tests where no Ref. Signal For tests where Ref. Signal
boosting is applied boosting is applied, e.g. ρA = -3dB

Fixed reference channels
Parameter Unit Value
Channel bandwidth MHz 1.4 3 5 10 15 20
Allocated resource blocks 6 15 25 50 75 100
Subcarriers per resource block 12 12 12 12 12 12
Allocated subframes per Radio Frame 10 10 10 10 10 10
Modulation QPSK QPSK QPSK QPSK QPSK QPSK
Target Coding Rate 1/3 1/3 1/3 1/3 1/3 1/3
Number of HARQ Processes Processes 8 8 8 8 8 8
Maximum number of HARQ transmissions 1 1 1 1 1 1
Transport block CRC Bits 24 24 24 24 24 24
Number of Code Blocks per Sub-Frame
(Note 4)
For Sub-Frames 1,2,3,4,6,7,8,9 Bits 1368 3780 6300 13800 20700 27600
For Sub-Frame 5 Bits n/a n/a n/a n/a n/a n/a
For Sub-Frame 0 Bits 528 2940 5460 12960 19860 26760
Max. Throughput averaged over 1 frame kbps 341.6 1143.2 1952.8 3952.8 6040.8 7884
UE Category 1-5 1-5 1-5 1-5 1-5 1-5

Fixed reference channels defined in TS 36.101 for receiver quality measurements


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

Channel bandwidth
E-UTRA
1.4 MHz 3 MHz 5 MHz 10 MHz 15 MHz 20 MHz Duplex
Ban
(dBm) (dBm) (dBm) (dBm) (dBm) (dBm) Mode
d
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
Extract from TS 36.521

Sensitivity depends on band,
channel bandwidth and RMC
under test

Block Error Ratio and Throughput

Rx
quality
DL
signal

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


Details LTE FDD signaling
Rx Measurements

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

l Calculating
l BLER (NACK/ALL)
l Throughput [kbps]


Rx measurements: BLER definition

PDCCH, scheduling info

PDSCH, as PRBS
Count
#NACKs
and ACK/NACK feedback
calculate
BLER
Assumption is that eNB
Power = UE Rx power


Rx measurements: BLER definition
PDCCH, scheduling info •ACK = UE properly
Receives PDCCH + PDSCH
•NACK = UE properly receives
PDCCH but does not understand
PDSCH
•DTX = UE does not understand
PDSCH, user data PDCCH

ACK/NACK feedback

# NACK  # DTX
# ACK BLER =
ACK relative = # ACK  # NACK  # DTX
# ACK  # NACK  # DTX
# NACK
NACK relative =
# DTX
DTX relativ =


BLER verification
Downlink error
insertion to verify
the UE reports


Transportation Block Size Index
Transportation block size TBS Idx Modulation

User data FEC 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


Throughput versus SNR


UE sensitivity – maximum input level

Maximum input level

Rx Parameter Units Channel bandwidth

Wanted signal mean power dBm -25


UE sensitivity – RF sensitivity measurement

ACK/NACK
PRBS

minimum input level

Channel bandwidth
E-UTRA
1.4 MHz 3 MHz 5 MHz 10 MHz 15 MHz 20 MHz Duplex
Ban
(dBm) (dBm) (dBm) (dBm) (dBm) (dBm) Mode
d
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


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] [3MHz] 5MHz
Padj = -51.3
Padj = -53.5

ACS= 33dB
Padj = -57.5

ACS= 33dB
ACS= 33dB

Pown= -82.3
2dB IM
Pown= -84.5 Nt= -84.3
2dB IM
Pown= -88.5 Nt= -86.5
2dB IM
Nt= -90.5
1.4MHz LTE 1.4MHz LTE 3MHz LTE 3MHz LTE 5MHz LTE 5MHz LTE
1.4MHz 3MHz 5MHz

10MHz 15MHz 20MHz
Padj = -48.3
Padj = -49.5 Padj,w cdma= -51.3
ACS= 33dB

ACS=
30dB

27dB
ACS=
Pow n= -76.3
Pown= -77.5 2dB IM
Pown= -79.3 2dB IM Nt= -78.3
2dB IM Nt= -79.5
Nt= -81.3

10MHz LTE 5MHz LTE 15MHz LTE 5MHz LTE 20MHz LTE 5MHz LTE

7.5MHz 10MHz 12.5MHz


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 10 MHz 15 MHz 20 MHz

ACS dB 33.0 33.0 33.0 33.0 30 27

Rx Parameter Units Channel bandwidth

Wanted signal dBm
mean REFSENS + 14 dB
power
dBm REFSENS REFSENS REFSENS REFSENS REFSENS REFSENS
+45.5d +45.5 +45.5dB* +45.5d +42.5d +39.5dB
PInterferer B dB B B
BW Interferer MHz 1.4 3 5 5 5 5
FInterferer (offset) MHz 1.4+0.0025 / 3+0.0075 5+0.0025 7.5+0.0075 10+0.0125 12.5+0.0025
-1.4-0.0025 / / / / /
-3-0.0075 -5-0.0025 -7.5-0.0075 -10-0.0125 -12.5-0.0025


Receiver performance - Blocking tests
5MHz LTE interferer
In-band blocking 15MHz below to 15MHz above the UE receive band

CW interferer , more than 15MHz below to
Out-of-band blocking 15MHz above the UE receive band

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

Throughput
shall be ≥
f >> system bandwidth 95%


fB fc
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 N RB
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
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 Frequency
E-UTRA
band range 1 range 2 range 3 range 4

PInterferer dBm -44 -30 -15 -15

1, 2, 3, 4, 5, FDL_low -15 to FDL_low -60 to FDL_low -85 to
-
6, 7, 8, 9, 10, FDL_low -60 FDL_low -85 1 MHz
11, 12, 13,
FInterferer
17, 18, 19, MHz
(CW) FDL_high +15 to FDL_high +60 to FDL_high +85 to
20, 21, -
33,34,35,36,3 FDL_high + 60 FDL_high +85 +12750 MHz
7,38,39,40
2, 5, 12, 17 FInterferer MHz - - - FUL_low - FUL_high

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


Rx quality - Intermodulation
Throughput Wanted Signal C
shall be ≥ Unmodulated
95% Interferer Icw

f f
Modulated
Interferer Imod

fc fcw fmod frequency
See TS 36.101 for power and frequency offset definitions


CQI reporting
Optimum throughput ≡CQIn+2
high if the UE reports
Overrated CQIn ≡CQIn+1

Throughput
CQI report
≡CQIn

≡CQIn-1
≡CQIn-2
Underrated
CQI report
low
Prevailing conditions of SIR

low SIR changes, CQI reporting must follow! high
SIR


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% BLER on median CQI > 10%
Network sends CQI +1 Network sends CQI -1
-> BLER must be -> BLER must be
> 10% < 10%


Rx tests – test mode
UE SS

ACTIVATE TEST MODE
Test modes defined to perform
ACTIVATE TEST MODE
COMPLETE
Rx measurements, loop back
possible in test mode

UE SS

CLOSE UE TEST LOOP

CLOSE UE TEST LOOP COMPLETE


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

Test loop mode A
UE Test Loop Mode A Function

u0,u0 .......u K .................u N -1
u 1,u1 .......uK -1 u0,u 1 .......uK -1

User data User data
Uplink
and downlink
Down link Uplink
may have
UE Test Loop Mode A Function
various
capacity

u0 .. uK -1 ..uN-1 u0...uN -1 u0...uN -1 u0..uK-1

User data User data

Down link Uplink

Test loop mode B

Loop back above
PDCP, i.e. Layer 2

Protocol PDCP

PDU size buffer
must match
ΔΤ

Delayed loop back

Throughput measurements

Max throughput
possible in SISO


Rx measurements - throughput

Throughput
Measurement,
Settings for max
throughput
for SISO:

Number of
Resource blocks

Modulation scheme

Transport block size


LTE Downlink BLER and throughput

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


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

UE sends
different
CQI
values


MIMO testing
For MIMO, enable cell

One antenna Two antennas Four antennas

 1 4 
 1  9  9   MIMO correlation
1   19 * 1 4 
ReNB  1     1  9  9
 4 * 1 *
eNode B Correlation ReNB  1 
ReNB
 1  Models from
  
9  9 1  9
 *
  
4 * 1
9  9
*

1  TS 36.521


MIMO in LTE: BLER and throughput


Throughput measurements

MIMO active,
2 streams with
different data rate


Why do we need fading?

l 3GPP specifies various tests under conditions of fading
l WCDMA performance tests
l HSDPA performance tests
l LTE performance tests
l LTE reporting of channel state information tests

See CMW capability lists for details

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


Most popular MIMO scheme to increase data rates:
Spatial Multiplexing
h 11
h 12
TX
Ant 1
h 21
Space
h22 RX
Matix B Ant 1
n1
TX
d1 Ant 2 RX r1 de1
Ant 2 MIMO
LO
2X2 RX
d2 (e.g. ZF,

MIMO r2
MMSE,MLD)
de2

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.


How do we test under conditions of fading?

RF
System
simulator

Channel emulator
Fading Profile


How do we test under conditions of fading?

System
simulator
IQ IQ RF
Out In
I/Q Interface
Option
CMW-B510x
IQ IQ
In Out

Channel emulator

Fading Profile


Internal fading in LTE


BLER results with and without fading


Automatic testing: KT100 LTE + internal fading


Measurement sample (open loop SM)


BLER vs. SNR Transmit/Receive Diversity

~2dB

AWGN only
MCS 7 and 10

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


GUI – IP Settings


LTE E2E using DAU


Throughput end to end


End to end testing – ping response, RTT


What is IMS?
A high level summary
l The success of the internet, using the Internet Protocol (IP) for
providing voice, data and media has been the catalyst for the
convergence of industries, services, networks and business models,
l IP provides a platform for network convergence enabling a
service provider to offer seamless access to any services, How to
anytime, anywhere, and with any device, merge IP
and cellular
l 3GPP has taken these developments into account world??
with specification of IMS,
l IMS stands for IP Multimedia Subsystem,
l IMS is a global access-independent and standard-based IP
connectivity and service control architecture that enables
various types of multimedia services to end-users using
common internet-based protocols,
l Defines an architecture for the convergence of audio,
video, data and fixed and mobile networks.


3 GPP System Architecture Evolution
Signaling interfaces

Data transport interfaces
RAN
Access PDN
directly or via IMS
MME PDN
UE Evolved nodeB

S-GW P-GW IMS
Evolved Packet Core PSTN
external

IMS to control
All interfaces are packet switched access + data
transfer

IMS Architecture


IMS protocol structure user plane
Control plane Voice messaging
video

SIP/SDP IKE RTP MSRP

UDP / TCP / SCTP

Layer 3 control IP / IP sec

Layer 1/2 Layer 1/2
(other IP CAN)
Mobile com specific protocols IMS specific protocols


IMS protocol structure Quality of Service
Media Transport
Media
Signaling Encap.
H.323 e.g. H.261, MPEG

application
layer Megaco SIP RTSP RSVP RTCP RTP

transport
layer TCP UDP

network
layer IPv4, IPv6

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

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


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


IMS Registration and Authentication
Comparison with LTE
LTE IMS

ATTACH REQUEST REGISTER

AUTHENTICATION REQ 401 UNAUTHORIZED

AUTHENTICATION RSP REGISTER

ATTACH ACCEPT 200 OK


What is IMS?
Registration with IMS
l Prior to IMS registration the UE must discover an IMS entry point
(i.e. P-CSCF), which is done through an activation of a PDP context
for SIP signaling over 2G (GPRS) or 3G (WCDMA, C2K, EV-DO).
l First, there was SIM (Subscriber Identity Retrieve S-CSCF
user profile
Module)…than there was USIM (Universal
SIM)…and now there is ISIM (IP Multimedia
Service Module),
– Public User Identity (identify a user), HSS
– Private User Identity (users subscription),
I-CSCF
Retrieve S-CSCF
capabilities

Calculate RES, REG request
SIP registration request

P-CSCF

401 User not authorized
200 OK


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


SMS over IMS

IP based Core
Access Network,
i.e. EPC
S-CSCF HSS

I-CSCF

P-CSCF
IP-SM-GW

IP short message
Gateway to connect
S-CSCF to SMS SMS-SC
serving centre


LTE Positioning with SUPL 2.0

LTE radio
signal

eNB
Measurements based on reference sources*

Target LPP
Location
Device Server
Assistance data

LPP over RRC
UE Control plane solution E-SMLC Enhanced Serving
Mobile Location Center

LPP over SUPL
SUPL enabled
Terminal
SET User plane solution SLP 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 Technical challenges offering circuit-switched services (Voice, SMS)
via LTE

l 3GPP has defined IMS as long-term solution providing
circuit-switched services, for the short- / mid-term there is
no industry-wide consensus, but different approaches,
l Short-/mid-term: Circuit-switched fallback (CS fallback),
– SMS. “SMS over SG”, means SMS via Non-Access Stratum (NAS)
signaling,
– Voice. Fallback to 3G or 2G technology to take the call,
l VOLGA – Voice over LTE Generic Access
– Call setup time increases while using CS fallback,
l OneVoice Initiative formed to push for Voice over LTE (VoLTE)
based on IMS.

How to connect E-UTRAN to CS services?
l 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


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


Voice over IMS: IMS call establishment
Originating Home Network Terminating
Network
UE P-CSCF S-CSCF

1. Invite (Initial SDP Offer)


3. Service Control


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)



16. Reservation Conf

22. Ringing
23. Ringing
24. Ringing
26. 200 OK
27. 200 OK
25. Alert User
28. Enabling of
Media Flows
29. 200 OK

30. Start Media

31. ACK
32. ACK
33. ACK


Voice over IMS: IMS protocol profile
Adaptive Multirate Codec mode
AMR_12.20
Source codec bit-rate
12,20 kbit/s (GSM EFR)
Codecs are used AMR_10.20
AMR_7.95
10,20 kbit/s
7,95 kbit/s
In VoIP over IMS 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_SID 1,80 kbit/s (see note 1)


QoS class identifiers QCI
QCI Resource Priority Packet Delay Packet Error Example Services
Type Budget Loss
Rate

1 2 100 ms 10-2 Conversational Voice

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

Video (Buffered Streaming)
6 6 300 ms TCP-based (e.g. www, e-mail, chat, ftp, p2p
10-6
file sharing, progressive video, etc.)
Non-GBR Voice, Video (Live Streaming),
7 7 100 ms
10-3 Interactive Gaming

8 8 Video (Buffered Streaming)
300 ms TCP-based (e.g. www, e-mail, chat, ftp, p2p
9 9 10-6 file sharing, progressive video, etc.)


Voice over LTE – protocol profiles
AMR codec
Optimize transmission of
Voice by configuring UDP/ TCP
Lower layers IP

Use robust header compression or IP Packet Data Convergence
Short PDCP header is used PDCP

Use RLC in UM mode
Small sequence number is used Radio Link Control
RLC
SRB1 and 2 are supported for
DCCH + one UM DRB with QCI 1 for voice
for SIP signaling + one AM DRB QCI 5 for Medium Access Control
SIP signaling + one AM DRB QCI 8 for MAC
IMS traffic

TTI bundling + DRX to reduce PDCCH
Signaling + Semi-persistend scheduling PHYSICAL LAYER


IMS: Voice over IMS
Interaction with EPS

l Resource reservation (QoS) can
be achieved with separate Radio
Bearers Default Dedicated
Bearer Bearer

SIP Non-
QCI = 5 AM DRB
signalling GBR

PDCP
Voice QCI = 1 GBR UM DRB
RLC
QCI Quality of Service Class Indicator
GBR Guaranteed Bitrate MAC
DRB Data Radio Bearer
PHY

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 HSS

I-CSCF
How to connect VoLTE
P-CSCF
To legacy network?

PSTN BGW
CS
network
MGCF BGCF
User plane
MG


IMS connection to CS services - arguments

l IMS can provide real end-to-end connection
l IMS defines end-to-end quality of service profiles
l IMS is completely based on Internet Protocol
l Supplementary services can be realized
l Several application servers needed
l Not widely implemented yet – many operators are reluctant
l IMS software client needed on UE side
l What happens under heavy load condition?


Radio Access Technologies today

GERAN CDMA2K
1xEVDO
UTRAN

EUTRAN

LTE coverage is not fully up from day one
-> interworking with legacy networks is essential!!!


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

But….

What if IMS is not available at first rollout?
-> interim solution called Circuit Switched Fallback CSFB = handover to
2G/3G
-> or Simultaneous Voice on 1XRTT and LTE, SV-LTE = dual receiver

What is if LTE has no full coverage?
-> interworking with existing technologies, Single Radio Voice Call Continuity,
SRVCC


2G or 3G CS fallback
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


2G or 3G CS fallback
CS
connection
as fallback SGSN
to legacy GERAN Voice calls are
networks
routed via 2G or 3G

UE UTRAN
MSC

E-UTRAN MME Only for signalling

Only packet switched connections


CSFB issues and questions
Iu-ps SGSN
Target cell UTRAN
assigned or
Gs
selected by UE? Gb
Uu
GERAN
S3 Iu-cs
MSC
Um A Server

SGs
LTE Uu S1-MME
UE E-UTRAN 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?

CS fallback options to UTRAN and GERAN

Feature
group
index, UE
indicates
CSFB
support


CS fallback to 1xRTT

1xCS
CSFB 1xRTT CS A1 1xRTT
UE Access MSC
A1

Tunneling of 1xCS IWS S102 is the
messages between reference point
1xRTT MSC and UE
S102 between MME and
MME 1xCS interworking
S1-MME S11 solution
1xCS Serving/PDN SGi
E-UTRAN
CSFB GW
UE S1-U

Tunnelled 1xRTT messages


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


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


Dual receiver 1xCSFB
Circuit switched
UE 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!


SV-LTE: Simultaneous CDMA200 + LTE

Circuit switched
UE 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


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, …


OTT – over the top - arguments
EUTRAN

Application
UE 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


SMS transfer in LTE
Encapsulate SMS in NAS
Send SMS over IMS
Control message->
Using IP protocol
SMS over SG
SMS over IMS
EMM ESM User plane
Radio Resource Control
RRC
PDCP
Radio Bearer
Measurements

Radio Link Control
Control &

RLC
Logical channels
Medium Access Control
MAC
Transport channels
PHYSICAL LAYER


CSFB circuit switched fallback – SMS transfer

Iups
- SGSN SMS-SC
UTRAN

Gs
Gb
Uu
GERAN
Iu cs
-
S3
MSC
Um A Server

For 1xRTT it
LTEUu
- S1-MME SGs is the S102
UE E-UTRAN MME interface

SGsAP SGsAP

SMS transfer between SMS-SC and SCTP SCTP

IP IP
MME via new interface SGs. L2 L2
New protocol SGs interface L1 L1

application protocol MME SGs MSC Server


SGs interface
SMS-
SMS-
MS/UE eNodeB MME MSC/VLR HLR/HSS SC
GMSC
1. EPS/IMSI attach procedure
2. Message transfer
3. Send Routeing Info For Short Message
4. Forward Short Message
5. Paging
7. Paging 6. Paging

8. Service Request
8a. Service Request No real fallback,
9a. Downlink Unitdata because SMS
9b. Downlink NAS Transport
9c. Uplink NAS Transport 9d. Uplink Unitdata is sent over
NAS signaling
10. Uplink NAS Transport 11. Uplink Unitdata

12. Delivery report
13. Delivery report
15. Downlink NAS Transport 14. Downlink Unitdata

16. Release Request

Mobile terminated SMS in idle mode, SMS over SG



l SMS can be transferred in the signaling messages
-> so no real circuit switched fallback
l CSFB ready at LTE launch? CSFB needs SGs
interface between MME and MSC
l Roaming: no guarantee that CSFB is supported
worldwide
l Specification issues: Not clear what happens if
SMS transfer occurs at ongoing CSFB procedure
l Test scenarios: No CSFB SMS test scenarios
defined yet


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


SRVCC – Single Radio Voice Call Continuity
SGSN
GERAN Handover of voice call
to 2G or 3G

UE UTRAN
MSC

E-UTRAN MME IMS

User plane after handover SRVCC is handover from
EUTRAN to 2G/3G if no
User plane before handover
LTE coverage

Target
UE E-UTRAN MME MSC Server 3GPP IMS
UTRAN/GERAN

Measurement
Reports

Handover to UTRAN/GERAN
required

Initiates SRVCC for voice component

CS handover preparation
Handles PS-PS HO for
non-voice if needed IMS Service Continuity Procedure

To eUTRAN
PS HO response to MME
Coordinates SRVCC
(CS resources)
Handover CMD and PS HO response

Handover
execution



VoLTE call eNodeB = EUTRAN

Handover to UTRAN

VoIP in PS mode
NodeB = UTRAN

Radio Bearer reconfiguration:
PS to CS mode

time Voice call in CS mode NodeB = UTRAN


Handover requirements
l Goal is to have seamless service continuity between LTE and other Legacy
Technologies (CDMA2000, WCDMA, GSM)
l Data and Voice services
l Support of all frequency bands and a single radio solution
l Transparent signaling to allow an independent protocol evolution for both
access systems
l Impact to QoS, e.g. service interruption, should be minimized
l RAT change procedure shall limit interruption time to less than 300ms
l 3GPP changes
– Ability to tunnel signaling messages between E-UTRAN and 3GPP2
– Support measurements of 3GPP2 channels from E-UTRAN
– Capability to trigger a handover to a 3GPP2 system
l 3GPP2 changes
– Minimal impact on today’s available cdma2000, Rev. 0 or Rev. A access terminal
– Minimal impact to legacy, deployed cdma2000 radio access networks
– Influence on circuit switched core network should be minimized


Handovers??

l What is :
l Intra-Frequency
– Changing between cells on same frequency -> different cell ID
l Inter-Frequency
– Changing between cells on differenct frequency
l Intra-Band
– Changing between cells inside the same band
l Inter-Band
– Changing between cells in different bands
l Inter-RAT
– Changing between cells using different RAT (LTE-WCDMA, LTE-GSM,
etc.)


Handover – what to discuss?
UE reads GERAN cell(s)?
SysInfo

eNodeB
UTRAN cell(s)? EUTRAN cell
CDMA2K cell(s)? NW sends
UE Redirection command? SysInfo of
Target?
Will the UE initiate the Handover command?
change? -> re-selection
Will the network initiate Mandatory
the change? -> for UE
redirection or handover supporting
CSFB


Handover aspects – what to discuss?

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

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


Mobility aspects – support from UE

l There are some UE feature groups defined. The UE reports
this in the attach procedure to the network:

– A. Support of measurements and cell reselection procedure
in idle mode

– B. Support of RRC release with redirection procedure in
connected mode

– C. Support of Network Assisted Cell Change in connected
mode

– D. Support of measurements and reporting in connected
mode

– E. Support of handover procedure in connected mode

Mobility aspects – support from UE
Feature GERAN UTRAN HRPD 1xRTT EUTRAN
Supported if Supported if
CDMA200 CDMA200
GERAN UTRAN Supported for
A. Measurements and cell reselection 0 HRPD 0 1xRTT
band band supported
procedure in E-UTRA idle mode band band
support is support is bands
support is support is
indicated indicated
indicated indicated
CDMA200 CDMA200
B. RRC release with blind redirection GERAN UTRAN Supported for
0 HRPD 0 1xRTT
procedure in E-UTRA connected band band supported
band band
mode support is support is bands
support is support is
indicated indicated
indicated indicated
C. Cell Change Order (with or without)
Network Assisted Cell Change) in E- Group 10 N.A. N.A N.A N.A.
UTRA connected mode
D. Inter-frequency/RAT measurements,
reporting and measurement reporting
Group 23 Group 22 Group 26 Group 24 Group 25
event B2 (for inter-RAT) in E-UTRA
connected mode
Group 9
(GSM_conn
ected Group 8 (PS
handover) handover)
E. Inter-frequency/RAT handover procedure Separate UE or Group
Group 12 Group 11 Group 13
in E-UTRA connected mode capability bit 27
defined in (SRVCC
TS 36.306 handover)
for PS
handover

Table from TS36.331

LTE Radio Resource Control States
Cell search and selection 1. What about
de-allocate Tracking Area ID (TA-ID) and IP address
and system information mobility, when UE
acquisition
is in IDLE state?
LTE random access procedure
[Initial Access; allocate C-RNTI, TA-ID, IP address]
release of C-RNTI, allocate
DRX cycle for PCH

LTE_DETACHED LTE_ACTIVE (RRC_CONNECTED) LTE_IDLE (RRC_IDLE)
• No IP address assigned, • IP address assigned, • IP address assigned,
• UE location unknown. • Connected to known cell. • UE position partially known.
OUT_OF_SYNCH IN_SYNCH
• DL reception possible, • DL reception possible,
• No UL transmission. • UL transmission possible.
Power-up
© Rohde&Schwarz, 2010
[Transition to LTE_ACTIVE state (IN_SYNCH)]
[to restore uplink synchronization]

2. What about
User Equipment (UE)
LTE/eHRPD-capable terminal mobility, when UE
is in CONNECTED state?


Mobility between LTE and WCDMA/GSM
Radio Access Aspects

GSM_Connected
CELL_DCH Handover E-UTRA Handover
RRC_CONNECTED
GPRS Packet
transfer mode
CELL_FACH
CCO with
optional CCO,
CELL_PCH NACC Reselection
URA_PCH Reselection
Connection Connection
Connection establishment/release establishment/release
establishment/release

Reselection E-UTRA Reselection GSM_Idle/GPRS
UTRA_Idle
RRC_IDLE Packet_Idle
CCO, Reselection


IRAT Procedures
Redirection

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

2. NW releases RRC connection and indicates target RAT and RF
channel in RRC Connection Release Message

3. UE indicates active PDP Contexts during Routing Area Update
procedure on target RAT

4. NW sets up radio bearer

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

6. Data connection is interrupted during the procedure


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

UE EUTRAN

RRCConnectionRelease


Redirection to UMTS
UE reads
SysInfo

eNodeB
NodeB(s) EUTRAN cell
UTRAN cell(s)
RRC connection release message
UE will search for UE with RedirectedCarrierInfo to
suitable cell on
UARFCN and initiate
UTRAN Mandatory
for UE
CS connection supporting
CSFB

RRC connection release with redirection without SysInfo


Redirection to UMTS Rel. 9
feature
UE reads
SysInfo

NodeB eNodeB
Sys
UTRAN cell Info EUTRAN cell

UE will go to indicated UE with RedirectedCarrierInfo to
cell and initiate CS
connection UTRAN
e-RedirectionUTRA
capability is set
by UE

RRC connection release with redirection with SysInfo


Redirection to GERAN

eNodeB
BTS(s) EUTRAN cell
GSM cell(s)
suitable cell on ARFCN
and initiate CS
GSM Mandatory
for UE
connection supporting
CSFB



Redirection to GERAN Rel. 9
feature

BTS(s) eNodeB
Sys
GSM cell(s) Info EUTRAN cell

UE will go to indicated UE with RedirectedCarrierInfo to
cell and initiate CS
connection GSM
e-RedirectionUTRA
capability is set
by UE

RRC connection release with redirection with SysInfo


IRAT Procedures
PS Handover

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

l NW sends handover command e.g.
l LTE → WCDMA: MobilityFrom EUTRACommand
l WCDMA → LTE: HandoverFromUTRANCommand_EUTRA

l PS radio bearer is immediately setup on target RAT


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

UE EUTRAN

RRCConnectionReconfiguration

RRCConnectionReconfigurationComplete


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 {}
}
}


Handover (Intra-MME/Serving Gateway)
UE Source eNB Target eNB MME

Measurement reporting
Handover decision
Handover request
Admission Control
Handover request Ack
RRC connection reconfiguration
Detach from old, Deliver packets
sync to new cell to target eNB
SN Status Transfer
Data forwarding
Buffer packets
from source eNB
RRC connection reconfiguration complete
Path switch Req / Ack
UE context release
Flush buffer
Release resources

Handover to UMTS: Packet switched
handover

eNodeB
NodeB(s) EUTRAN cell
UTRAN cell(s)
UE MobilityFromEUTRACommand message
UE will select target cell
on UARFCN and with purpose indicator = handover
continue PS connection to UTRAN
EUTRAN contains targetRATmessagecontainer,
= Inter-RAT info about target cell

Packet Switched handover to UTRAN


HandoverfromEUTRAN – target RAT
message
HandoverFromEUTRAN message contains control message
of target RAT. Possible messages are:
targetRAT-Type Standard to apply targetRAT-MessageContainer

geran
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

cdma2000- C.S0001 or later, C.S0007 or later,
1XRTT C.S0008 or later

cdma2000- C.S0024 or later
HRPD
utra 3GPP TS 25.331 HANDOVER TO UTRAN
COMMAND


Mobility from EUTRAN – failure case

UE EUTRAN

MobilityFromEUTRACommand

RRC connection re-establishment

Radio link failure UE will try to
in target RAT Reestablish
EUTRAN connection


UE mobility in LTE (RRC CONNECTED state)
Measurement configuration, related RRC messages & information elements
RRCConnectionReconfiguration
…
MeasConfig Neig Cell Info
... MeasConfig Type of CDMA network (1xRTT, HRPD),
MeasObjectToAddModList CDMA2000 carrier configuration, search
ReportConfigToAddMod window size, cells to add/modify/remove
QuantityConfig from the neighboring list, cell index (up to
measGapConfig 32 cells), PN offset…
MeasObjectToAddModList
…
MeasObjectCDMA2000

How? What? Periodic or event (InterRAT: B1, B2) triggered
When? Reporting, hysteresis (0…15 dB), # of cells to
report excluding serving cell, report interval
ReportConfigToAddMod (120, …, 10240ms, …, 60 min), time-to-trigger,
… CDMA2000 threshold (0…63)
ReportConfigInterRAT

measGapConfig
Each gap starts at SFN & subframe gp0 (0…39), gp1 (0…79)
meeting these conditions : Two gap pattern 0 and 1, gap length is 6 ms,
using two different Transmission Gap
SFN mod T = FLOOR(gapOffset/10) Repetition Period of 40 or 80 ms
with T = MGRP/10
Subframe = gapOffset mod 10
When to retune the receiver to measure e.g. CDMA2000 or HRPD…


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

eNodeB
BTS(s) EUTRAN cell
GPRS cell(s)
MobilityFromEUTRACommand message
UE with purpose indicator = Cell Change Order
UE will search for
to GPRS
Mandatory
and re-initiate PS for UE
CSFB

Packet Switched cell change order to GPRS without NACC
(network assisted cell change)


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

BTS eNodeB
Sys
GPRS cell Info EUTRAN cell
MobilityFromEUTRACommand message
UE with purpose indicator = Cell Change Order
UE will search for
to GPRS
Mandatory
and initiate PS for UE
CSFB

Packet Switched cell change order to GPRS with NACC
(network assisted cell change)


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

BTS eNodeB
GPRS cell EUTRAN cell

UE will search for MobilityFromEUTRACommand message
suitable cell on ARFCN UE with purpose indicator = handover
and continue PS to GPRS
connection Mandatory
for UE
supporting
CSFB

Packet Switched handover to GPRS


LTE-RTT Handover
Circuit Switched Fallback,
CSFB
Overview


3GPP Changes
l LTE Broadcast Channel
l CDMA System Time
l 1xEVDO, 1xRTT, WCDMA, GSM cell parameters
l Cell (re)selection parameters
l Broadcast as SIB Type 8 or via Dedicated RRC messages

l Tunneling
l Receiving 1xEVDO overhead messages with dual Rx ATs

l Measurement Gaps


Eg CDMA2000 Changes
l Air interface specification changes
l New protocols defined for
– Authentication: EAP-AKA
– IP Address Allocation : VSNCP
– Multiple PDN support : EMFPA

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

l Core network changes
l S101 interface – signaling interface
l S103 interface – bearer interface
l PDSN extension (now called HSGW)


Definitions cont’d
l Non-Optimized Handovers
l Without the use of tunneled signaling (S101)

l Optimized Handovers
l Less than 300ms interruption
l Uses tunneled signaling interface
l Two step process
– Pre registration / Session maintenance
– Handover preparation/handover execution
l Types of handovers
– Idle mode handover (cell re-selection)
– Active mode handover



1xCS
CSFB 1xRTT CS A1 1xRTT
UE Access MSC
A1

Tunneling of 1xCS IWS S102 is the
messages between reference point
1xRTT MSC and UE
S102 between MME and
MME 1xCS interworking
S1-MME S11 solution
1xCS Serving/PDN SGi
E-UTRAN
CSFB GW
UE S1-U

Tunnelled 1xRTT messages


CSFB to 1xRTT
MME
CSFB Info

eNodeB
1xRTT cell(s) EUTRAN cell

suitable cell on
UARFCN and initiate
1xRTT Mandatory
for UE
CS connection supporting
CSFB
Enhancement: UE can pre-register in 1xRTT network to 1xRTT



UE E-UTRAN MME 1xCS IWS
1xRTT S-GW/
MSC P-GW

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


enhanced 1xCSFB (e1xCSFB)
Enhancement: UE can pre-register in 1xRTT network
UE EUTRAN
1) Prepare for
handover,
search for HandoverFromEUTRAPreparationRequest

1xRTT

Time flow
UE EUTRAN
2) Info about
1xRTT ->
tunnelled via ULHandoverPreparationTransfer

S102

UE EUTRAN
3) Includes
1xRTT channel
assignment MobilityFromEUTRACommand


enhanced 1xCSFB (e1xCSFB) + concurrent HRPD handover
Enhancement: UE can pre-register in 1xRTT network
1) Prepare for UE EUTRAN
handover,
search for
HandoverFromEUTRAPreparationRequest
1xRTT + HRPD

2) Trigger 2 UE EUTRAN
Time flow
messages with ULHandoverPreparationTransfer
info about
1xRTT + HRPD UE EUTRAN

ULHandoverPreparationTransfer

UE EUTRAN
3) Redirection
to 1xRTT and
handover to MobilityFromEUTRACommand
HRPD


LTE-eHRPD Handover
Overview


InterRAT Network Architecture
Eg CDMA2000 1xEVDO


EUTRAN – eHRPD non-roaming

i.e. US subscriber, connected
To home network, leaves
LTE coverage area


EUTRAN – eHRPD, roaming case

i.e. European subscriber
visiting US, connected to roaming
network and leaving LTE
coverage area

Mobility between LTE and HRPD
Radio Access Aspects
No handover to
EUTRAN

HRPD active to EUTRAN is
always cell reselection
(via RRC idle)

3 Step Procedure

Ability of pre- E-UTRAN needs
registration is to decide, that
indicated HO to HRPD
on PBCCH is required

UE attached
Pre-registration HO preparation HO execution
to E-UTRAN

• Reduces time for cell re-selection or handover
• Reduces risk of radio link failure

Connection Request Traffic Channel Assignment
issued by UE to command is delivered
HRPD, HRPD prepares to UE, re-tune radio to
for the arrival of the UE HRPD channel, acquire
HRPD channel, session
configuration


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

Introduction

l Cisco quote 06/2011
l Internet video is now 40 percent of
consumer Internet traffic, and will reach
62 percent by the end of 2015, not
including the amount of video ex-
changed through P2P file sharing. The
sum of all forms of video (TV, video
on demand [VoD], Internet, and P2P)
will continue to be approximately 90
percent of global consumer traffic by 2015.
l IDC quote 06/2011
l The fast-growing smartphone market, which will
grow more than four times the rate of the overall
mobile phone market this year, is being fuelled
by falling average selling prices, increased
phone functionality, and lower-cost data plans
among other factors, which make the devices
more accessible to a wider range of users.


Introduction
Network view Impact due to
EPC / IMS l Packet delay
l Packet jitter
l Packet loss
MME PCRF l …

Node B

SGW PGW
Impact due to
Internet
l Multipath propagation
l Speed
l …

Node B


Introduction
Testing real life conditions in the lab
l Main use cases from a test engineer (operator, manufacturer) perspective:
l Exploring the performance of mobile equipment from the end user perspective
l Measuring E2E throughput with realistic radio conditions
l Evaluating mobility performance
R&S®AMU200 Contest SW
baseband fader provides
simulates real life automation
radio conditions and reporting
capabilities

R&S®CMW500
emulates LTE
network

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


Video transmission over LTE
Video quality…
l … is the perceived degradation of a processed video in
comparison to an ideal reference or the reality

l … can be used as an evaluation criteria for any kind of video
transmission or processing system as signal impairments will
happen in different stages

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


The video processing chain and possible sources for video
degradation
• Encoding artifacts Impairments on the The decoder is usually the less
(blocking) transmission link critical component. But in
can cause loss of conjunction with the video
• Video / audio delay
information despite processor, errors during the
• Buffer rules are active error conversion process (e.g. de-
violated correction interlacing) are possible

Transmission
link
(IP, cellular,
broadcast, etc.)
Encoder TX RX Decoder Video processor

Receiver
Uncompressed video Output on
Redundant Restoring the video Scaling and
SDI screen
information (static information; i.e. the conversion to output
SMPTE249/292/424 image parts) and picture sequence format
irrelevant data including redundant
(details) is omitted data


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

l Example procedure: MOS Quality

5 Excellent
A group of trained experts judge the video quality in a
4 Good
scale ranging from bad to excellent. The assessments are
3 Fair
averaged and result in to a Mean Opinion Score (MOS).
2 Poor
1 Bad

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

l Disadvantages:
l Time consuming and expensive
l Automation not possible


Objective quality assessment
l Mathematical calculation that approximate averaged results of
subjective quality assessment

l Divided into three categories:
l Full reference methods (FR)
l Reduced reference methods (RR)
l No-reference methods (NR)

l Advantage:
l Assessment automation is possible for various applications

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


Objective metric – peak signal-to-noise ratio (PSNR)
MAX I2 l Most commonly used for quality
PSNR  10  log10 ( ) measurements for image compression.
MSE
1 m 1 n 1 l
  I (i, j )  K (i, j )
Simple mathematical calculation but
MSE 
2
poor correlation with subjective
mn i 0 j 0 methods:
l Digital pixel values do not exactly represent
I(i,j) = original pixel the light stimulus on the human eye
l The summation is averaging errors without
K(i,j) = reconstructed pixel weighting them
MAX = maximum possible pixel value l The same PSNR values may result from
different kind of structural errors

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


Objective metric – structural similarity (SSIM)
Signal x Luminance
Measurement
l Improvement to traditional methods for
+ Contrast
Measurement
Luminance
Comparison
Similarity
quality measurements to improve
Measure consistency with human eye perception.
Signal y Luminance
÷ Contrast
Comparison
Combination

Measurement
Structure l Complex mathematical calculation but
Comparison fairly good correlation with subjective
+ Contrast
Measurement
methods.
÷
(2 x  y  C1 )(2 xy  C2 )
SSIM ( x, y ) 
(  x   y  C1 )( x   y  C2 )
2 2 2 2

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.


Correlation of objective metric with MOS

Reference:
Z. Wang, A. C. Bovik, H. R. Sheikh and E. P. Simoncelli, "Image quality assessment: From
(MSSIM = Mean SSIM) error visibility to structural similarity," IEEE Transactions on Image Processing, vol. 13, no. 4,
pp. 600-612, Apr. 2004.


Metric – visible error
l The shown objective metrics and their correlation with MOS are
calculated frame based
l Temporal masking effects need to be considered:
l Additional condition: e.g. for at least 6 frames SSIM below 0.7 (25 fps video)
1,2

1

0,8
Not visible
SSIM

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 21 23
Frame


Demo


Testing real life conditions in the lab

PC

Contest

TC Control

RF

Video

via MHL
or HDMI


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


Mobile high definition link (MHL)
MHL is…
l the leading audio/video interface for mobile devices
l utilizes the existing Micro-USB connector
l provides power to the mobile device

l Single Transition Minimized Differential
Signaling (TMDS) channel:
l Carries video, audio and auxiliary data
l Bit stream is modulated by a clock signal
l Single-wire Control Bus (CBUS)
l Configuration and status exchange
l Replaces the DDC bus in HDMI
l Carries the MHL Sideband Channel (MSC)
which provides high level control functions
l VBUS and associated ground
l Provide power between sink and source
l 5V, max. 0.5 A


Summary

l Video and voice are important services gaining momentum for
the fastest developing radio access technology ever - LTE
l Beside LTE functionality, testing voice/video quality is
essential to judge a good receiver implementation

l R&S provides you with profound expertise and
test solutions on both aspects
l Complete LTE test portfolio ranging from early R&D via IOT
and field testing until conformance and production
l Supplier of a complete range of TV broadcasting transmission,
monitoring and measurement equipment


There will be enough topics
for future trainings 

Thank you for your attention!

Comments and questions
welcome!


LTE Measurement: How to test a device

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LTE Measurement: How to test a device