LTE, UMTS Long Term Evolution LTE measurements – from RF to application testing Reiner Stuhlfauth
[email protected]
Training Centre Rohde & Schwarz, Germany Subject to change – Data without tolerance limits is not binding. R&S® is a registered trademark of Rohde & Schwarz GmbH & Co. KG. Trade names are trademarks of the owners. 2011 ROHDE & SCHWARZ GmbH & Co. KG Test & Measurement Division - Training Center This folder may be taken outside ROHDE & SCHWARZ facilities. ROHDE & SCHWARZ GmbH reserves the copy right to all of any part of these course notes. Permission to produce, publish or copy sections or pages of these notes or to translate them must first be obtained in writing from ROHDE & SCHWARZ GmbH & Co. KG, Training Center, Mühldorfstr. 15, 81671 Munich, Germany
Mobile Communications: Fields for testing l RF testing for mobile stations and user equipment
l RF testing for base stations l Drive test solutions and verification of network
planning l Protocol testing, signaling behaviour l Testing of data end to end applications
l Audio and video quality testing l Spectrum and EMC testing
November 2012 | LTE measurements|
2
Test Architecture RF-/L3-/IP Application-Test
November 2012 | LTE measurements|
3
LTE: EPS Bearer E-UTRAN
UE
EPC
eNB
S-GW
Internet
P-GW
Peer Entity
End-to-end Service
EPS Bearer
Radio Bearer
Radio
External Bearer
S1 Bearer
S5/S8 Bearer
S1
S5/S8
November 2012 | LTE measurements|
Gi
4
Mobile Radio Testing Adjust the downlink signal to how uplink is received
Generate downlink signal and send control commands
Perform RF measurements on received uplink
Core network
A mobile radio tester emulates a base station November 2012 | LTE measurements|
5
Mobile Radio Testing Generate downlink signal and send signaling information
Generate downlink signal No signaling
Signaling testing
November 2012 | LTE measurements|
Control PC
Non-Signaling testing
6
LTE measurements general aspects
November 2012 | LTE measurements|
7
LTE RF Testing Aspects
UE requirements according to 3GPP TS 36.521 Power
Transmit signal quality
Maximum
output power Maximum power reduction Additional Maximum Power Reduction Minimum output power Configured Output Power Power Control Absolution
Power Control Relative Power Control Aggregate Power Control ON/OFF
Power time mask
36.521: User Equipment (UE) radio transmission and reception
Frequency
error Modulation quality, EVM Carrier Leakage In-Band Emission for non allocated RB EVM equalizer spectrum flatness
Output RF spectrum emissions Occupied
bandwidth Out of band emissions Spectrum emisssion mask Additional Spectrum emission mask Adjacent Channel Leakage Ratio
Transmit Intermodulation
November 2012 | LTE measurements|
8
LTE RF Testing Aspects
UE requirements according to 3GPP, cont. Receiver characteristics: Reference
sensitivity level Maximum input level Adjacent channel selectivity Blocking characteristics In-band Blocking Out of band Blocking Narrow Band Blocking Spurious response Intermodulation characteristics Spurious emissions
Performance November 2012 | LTE measurements|
9
LTE RF Testing Aspects
BS requirements according to 3GPP l Transmitter Characteristics l Base station output power l Frequency error l Output power dynamics l Transmit ON/OFF power
l Output RF spectrum emissions (Occupied bandwidth, Out of band
emission, BS Spectrum emission mask, ACLR, Spurious emission, Co-existence scenarios,…) l Transmit intermodulation l Modulation quality TR 36.804: Base Station (BS) radio transmission and reception
November 2012 | LTE measurements|
10
LTE RF Testing Aspects
BS requirements according to 3GPP, cont. l Receiver Characteristics l Reference sensitivity level l Dynamic range l Adjacent Channel Selectivity (ACS)
l Blocking characteristics l Intermodulation characteristics l Spurious emissions
l
Performance
November 2012 | LTE measurements|
11
LTE RF Measurements – regional requirements l l
Regional / band-specific requirements exist (e.g. spurious emissions) Since UEs roam implementation has to be dynamic
Concept of network signaled RF requirements has been introduced with
LTE. - Network signaled value: NS_01 … NS_32 - transmitted as IE AdditionalSpectrumEmission in SIB2
November 2012 | LTE measurements|
12
LTE bands and channel bandwidth E-UTRA band / channel bandwidth E-UTRA Band
1.4 MHz
3 MHz
1
5 MHz
10 MHz
15 MHz
20 MHz
Yes
Yes
Yes
Yes Yes[1]
2
Yes
Yes
Yes
Yes
Yes[1]
3
Yes
Yes
Yes
Yes
Yes[1]
Yes[1]
4
Yes
Yes
Yes
Yes
Yes
Yes
5
Yes
Yes
Yes
Yes[1]
6
Yes
Yes[1]
7
Yes
Yes
Yes
Yes[1]
Yes
Yes[1]
9
Yes
Yes
Yes[1]
Yes[1]
10
Yes
Yes
Yes
Yes
Yes
Yes[1]
Yes[1]
Yes[1]
13
Yes[1]
Yes[1]
14
Yes[1]
Yes[1]
Yes[1]
Yes[1]
33
Yes
Yes
Yes
34
Yes
Yes
Yes
8
Yes
Yes
11 12
Yes
Yes
... 17 ...
Not every channel bandwidth for every band! Yes
35
Yes
Yes
Yes
Yes
Yes
Yes
36
Yes
Yes
Yes
Yes
Yes
Yes
37
Yes
Yes
Yes
Yes
38
Yes
Yes
Yes
Yes
39
Yes
Yes
Yes
Yes
40
Yes
Yes
Yes
Yes
NOTE 1: bandwidth for which a relaxation of the specified UE receiver sensitivity requirement (Clause 7.3) is allowed.
November 2012 | LTE measurements|
13
RF power
Tests performed at “low, mid and highest frequency” Nominal frequency described by EARFCN (E-UTRA Absolute Radio Frequency Channel Number)
lowest EARFCN possible and 1 RB at position 0
RF power
Frequency = whole LTE band mid EARFCN and 1 RB at position 0
RF power
Frequency
Highest EARFCN and 1 RB at max position Frequency November 2012 | LTE measurements|
14
Test Environment – Test System Uncertainty 36.101 / 36.508 • Temperature/Humidity -normal conditions +15C to +35C, relative humidity 25 % to 75 % -extreme conditions -10C to +55C (IEC 68-2-1/68-2-2) • Voltage • Vibration Acceptable Test System Uncertainty (Test Tolerance, TT) defined for each test individually in 36.521 Annex F (will be ignored further on for the sake of simplicity) Test
6.2.2. UE Maximum Output Power
Minimum Requirement in TS 36.101
Test Tolerance (TT)
Test Requirement in TS 36.5211
Power class 1: [FFS] Power class 2: [FFS] Power class 3: 23dBm ±2 dB Power class 4: [FFS]
0.7 dB 0.7 dB 0.7 dB 0.7 dB
Formula: Upper limit + TT, Lower limit - TT Power class 1: [FFS] Power class 2: [FFS] Power class 3: 23dBm ±2.7 dB Power class 4: [FFS]
November 2012 | LTE measurements|
15
LTE RF measurements on base stations
November 2012 | LTE measurements|
16
OFDM risk: Degradation Channel (ideal)
rl n
sl n
Samples
1 TMC
f f0
f1
f2
f0
f3
November 2012 | LTE measurements|
17
f1
f2
f3
OFDM risk: Degradation due to Frequency Offset Channel
e j 2fn rl n
sl n
Samples
f
f f0
f1
f2
f0
f3
November 2012 | LTE measurements|
18
f1
f2
f3
OFDM risk: Degradation due to Clock Offset Channel
sl n
rl n
Samples
f k
f f0
f1
f2
f0
f3
November 2012 | LTE measurements|
19
f1
f2
f3
Subcarrier zero handling Subcarrier 0 or DC subcarrier causes problems in DAC for direct receiver strategies, DC offset!
Downlink: sl( p ) t
1
DL RB k N RB N sc / 2
f-1
DL RB N RB N sc / 2 j 2kf t N CP ,l Ts ( p) a k ( ) ,l e ak( (p)) ,l e j 2kf t NCP ,lTs
f+1
DC subcarrier, suppressed
k 1
1/TSYMBOL=15kHz
Uplink: sl t
N RBULNscRB / 2 1
UL RB k N RB N sc / 2
a k ( ) ,l e
j 2 k 1 2 f t N CP ,l Ts
f-1
½ subcarrier offset November 2012 | LTE measurements|
f0
f1
DC subcarrier 20
f
LTE: DC subcarrier usage
DC subcarrier or subcarrier 0 is not used in downlink! November 2012 | LTE measurements|
21
DC offset – possible reasons DC offset originated by mixer:
fRX=fLO+fBB+fLO_ɛ fLO_ɛ
1st mixer
fBB=fRx-fLO fLO –fLO_ɛ=DC
fLO
fBB + DC Non-linearities of Amplifier also cause DC in the signal
PLL
Idea: set PLL to frequency fLO to get frequency of baseband as fBB = fRX – fLO But: if synthesizer has leakage: fLO_ɛ will spread into the input: At the output we get direct current, DC! November 2012 | LTE measurements|
22
Base station test models Parameter
1.4 MHz
3 MHz
5 MHz
10 MHz
15 MHz
20 MHz
1
1
1
1
1
1
0.000
0.000
0.000
0.000
0.000
0.000
-inf
-inf
-inf
-inf
-inf
-inf
0.000
0.000
0.000
0.000
0.000
0.000
-inf
-inf
-inf
-inf
-inf
-inf
Reference, Synchronisation Signals RS boosting, PB = EB/EA Synchronisation signal EPRE / ERS [dB] Reserved EPRE / ERS [dB] PBCH PBCH EPRE / ERS [dB] Reserved EPRE / ERS [dB] PCFICH # of symbols used for control channels PCFICH EPRE / ERS [dB]
2
1
1
1
1
1
3.222
0
0
0
0
0
1
1
1
2
2
3
PHICH # of PHICH groups # of PHICH per group
2
2
2
2
2
2
-3.010
-3.010
-3.010
-3.010
-3.010
-3.010
0
0
0
0
0
0
# of available REGs
23
23
43
90
140
187
# of PDCCH
2
2
2
5
7
10
# of CCEs per PDCCH
1
1
2
2
2
2
# of REGs per CCE
9
9
9
9
9
9
# of REGs allocated to PDCCH
18
18
36
90
126
180
# of
REGs added for padding
5
5
7
0
14
7
0.792
2.290
1.880
1.065
1.488
1.195
-inf
-inf
-inf
-inf
-inf
-inf
# of QPSK PDSCH PRBs which are boosted
6
15
25
50
75
100
PRB PA = EA/ERS [dB]
0
0
0
0
0
0
# of QPSK PDSCH PRBs which are de-boosted
0
0
0
0
0
0
n.a.
n.a.
n.a.
n.a.
n.a.
n.a.
PHICH BPSK symbol power / ERS [dB] PHICH group EPRE / ERS [dB] PDCCH
PDCCH REG EPRE / ERS [dB] REG EPRE / ERS [dB] PDSCH
PRB PA = EA/ERS [dB]
November 2012 | LTE measurements|
23
TS 36.141 Defines several Test models For base station e.g. E-TM1.1
Base station unwanted emissions Spurious emissions ACLR •Adjacent channel leakage •Operating band unwanted emissions Spurious domain
ΔfOOB
Channel bandwidth
ΔfOOB
Spurious domain
RB
E-UTRA Band
Worst case: Ressource Blocks allocated at channel edge November 2012 | LTE measurements|
24
Adjacent Channel Leakage Ratio - eNB E-UTRA transmitted signal channel bandwidth BWChannel [MHz]
BS adjacent channel centre frequency offset below the first or above the last carrier centre frequency transmitted
Assumed adjacent channel carrier (informative)
Filter on the adjacent channel frequency and corresponding filter bandwidth
ACLR lim it
1.4, 3.0, 5, 10, 15, 20
BWChannel
E-UTRA of same BW
Square (BWConfig)
45 dB
2 x BWChannel
E-UTRA of same BW
Square (BWConfig)
45 dB
BWChannel /2 + 2.5 MHz
3.84 Mcps UTRA
RRC (3.84 Mcps)
45 dB
BWChannel /2 + 7.5 MHz
3.84 Mcps UTRA
RRC (3.84 Mcps)
45 dB
NOTE 1: BWChannel and BWConfig are the channel bandwidth and transmission bandwidth configuration of the E-UTRA transmitted signal on the assigned channel frequency. NOTE 2: The RRC filter shall be equivalent to the transmit pulse shape filter defined in TS 25.104 [6], with a chip rate as defined in this table.
Large bandwidth
Limit is either -13 / -15dBm absolute or as above November 2012 | LTE measurements|
25
Adjacent channel leakage power ratio
November 2012 | LTE measurements|
26
ACLR measurement Ref
0 dBm
Att
25 dB
* RBW
10 kHz
VBW
30 kHz
SWT 250 ms
*
0
A
-10 1 AP VIEW
-20
2 AP VIEW
-30
3 AP CLRWR
-40
-50
EXT 3DB
-60
UTRAACLR1 = 33 dB
UTRAACLR2 = 36 dB
UTRAACLR2bis = 43 dB
-70
-80
-90
Additional requirement for E-UTRA frequency band I, signaled by network to the UE
-100
Center
1.947 GHz
fUTRA, ACLR2
Date: 21.AUG.2008
15:51:00
2.5 MHz/
fUTRA, ACLR1
Span
fCarrier
November 2012 | LTE measurements|
27
25 MHz
Operating band unwanted emissions Narrow bandwidth Frequency offset of measurement filter -3dB point, f
Frequency offset of measurement filter centre frequency, f_offset
Minimum requirement
0 MHz f < 5 MHz
0.05 MHz f_offset < 5.05 MHz
5 MHz f < min(10 MHz, fmax)
5.05 MHz f_offset < min(10.05 MHz, f_offsetmax)
-14 dBm
100 kHz
10 MHz f fmax
10.05 MHz f_offset < f_offsetmax
-16 dBm (Note 5)
100 kHz
7 f _ offset 7dBm 0.05 dB 5 MHz
Measurem ent bandwidth (Note 1) 100 kHz
TS 36.104 defines several limits: depending on Channel bandwidth, additional regional limits and node B limits category A or B for ITU defined regions => Several test setups are possible! November 2012 | LTE measurements|
28
Operating band unwanted emissions
November 2012 | LTE measurements|
29
Unwanted emissions – spurious emission The transmitter spurious emission limits apply from 9 kHz to 12.75 GHz, excluding the frequency range from 10 MHz below the lowest frequency of the downlink operating band up to 10 MHz above the highest frequency of the downlink operating band Frequency range
Measurement Bandwidth
Note
9kHz - 150kHz
1 kHz
Note 1
150kHz - 30MHz
10 kHz
Note 1
100 kHz
Note 1
1 MHz
Note 2
30MHz - 1GHz
Maximum level
-13 dBm
1GHz – 12.75 GHz NOTE 1: NOTE 2:
Bandwidth as in ITU-R SM.329 [5] , s4.1 Bandwidth as in ITU-R SM.329 [5] , s4.1. Upper frequency as in ITU-R SM.329 [5] , s2.5 table 1
Spurious emission limits, Category A November 2012 | LTE measurements|
30
Spurious emissions – operating band excluded
November 2012 | LTE measurements|
31
Base station maximum power In normal conditions, the base station maximum output power shall remain within +2 dB and -2 dB of the rated output power declared by the manufacturer. BS
External PA
External device e.g. TX filter
(if any)
(if any)
cabinet
Test port A
Normal port for measurements
Towards antenna connector
Test port B
Port to be used for measurements in case external equipment is used November 2012 | LTE measurements|
32
LTE – DVB interference scenarios Adjacent channel leakage of Basestation x into DTT channel N is point of interest
For a BS declared to support Band 20 and to operate in geographic areas within the CEPT in which frequencies are allocated to broadcasting (DTT) service, the manufacturer shall additionally declare the following quantities associated with the applicable test conditions of Table 6.6.3.5.3-4 and information in annex G of [TS 36.104] : PEM,N Declared emission level for channel N P10MHz Maximum output Power in 10 MHz November 2012 | LTE measurements|
33
Base station receiver test Example: Rx test, moving condition
70% of required throughput of FRC, Fixed Reference Channel
November 2012 | LTE measurements|
34
Base station receiver test – HARQ multiplexing
UE sends PUSCH with alternating data and data with multiplexed ACK
November 2012 | LTE measurements|
35
Base station test – power dynamics Synchronisation time/frequency BS under Test
FFT 2048 RFcorrection
CPremov
100 RBs, 1200 sub carr
Per subcarrier Ampl. /Phase correction
Symbol Detection / decoding
EVM
Resource element Tx power: Distinguish: •OFDM symbol •Reference symbol
RETP
November 2012 | LTE measurements|
36
Downlink Power Reference Signal: Cell-specific referenceSignalPower (-60…+50dBm), signaled in SIB Type 2
PDCCH power depending on ρB/ρA
PDSCH power to RS, where NO reference signals are present, is UE specific and signaled by higher layers as PA. For PDSCH power in same symbol as reference signal an additional cell specific offset is applied, that is signaled by higher layers as PB.
[Power] -50.00 dBm
2011 © Rohde&Schwarz
PA = -4.77 dB -54.77 dBm
PB = 3 (-3.98 dB) -58.75 dBm
0
1
2
3
4
5
6
7
8
9
11
10
12
13
[Time]
OFDM symbols
RS EPRE = Reference Signal Energy per Resource Element EPRE PDSCH A / B EPRE RS
Reference signal power = linear average of all Ref. Symbols over whole channel bandwidth B PB A
November 2012 | LTE measurements|
A PA (with some exeptions for MIMO)
37
Base station test – output power dynamics Measure avg OFDM symbol power + Compare active and non-active case Ref. Symbol, always on OFDM Symbol not active! OFDM Symbol active! PDSCH # of 64QAM PDSCH PRBs within a slot for which EVM is measured
1
PRB PA = EA/ERS [dB]
0
0
0
0
0
0
# of PDSCH PRBs which are not allocated
5
14
24
49
74
99
Test model: E-TM2 Only 1 RB allocated
1
1
1
1
Test model: E-TM3.1 All RB allocated
1
PDSCH # of 64QAM PDSCH PRBs within a slot for which EVM is measured
November 2012 | LTE measurements|
6
15
38
25
50
75
100
DL Modulation quality: Constellation diagram LTE downlink: several channels can be seen (example): PDSCH with 16 QAM
PDCCH + PBCH with QPSK S-SCH with BPSK
CAZAC Sequences, Reference signals November 2012 | LTE measurements|
39
LTE RF measurements on user equipment UEs
November 2012 | LTE measurements|
40
LTE Transmitter Measurements 1 1.1 1.2 1.3 1.4 2 2.1 2.2 2.3 2.3.1 2.3.2 2.3.3 2.4 2.4.1 2.4.2 2.4.3 3 3.1 3.2 3.2.1 3.2.2 3.2.3 3.2.4 4 4.1 4.2 4.2.1 4.2.2 4.2.3 4.3 4.3.1 4.3.2 4.3.3 5
Transmit power UE Maximum Output Power Maximum Power Reduction (MPR) Additional Maximum Power Reduction (A-MPR) Configured UE transmitted Output Power Output Power Dynamics Minimum Output Power Transmit OFF power ON/OFF time mask General ON/OFF time mask PRACH time mask SRS time mask Power Control Power Control Absolute power tolerance Power Control Relative power tolerance Aggregate power control tolerance Transmit signal quality Frequency Error Transmit modulation Error Vector Magnitude (EVM) Carrier leakage In-band emissions for non allocated RB EVM equalizer spectrum flatness Output RF spectrum emissions Occupied bandwidth Out of band emission Spectrum Emission Mask Additional Spectrum Emission Mask Adjacent Channel Leakage power Ratio Spurious emissions Transmitter Spurious emissions Spurious emission band UE co-existence Additional spurious emissions Transmit intermodulation
November 2012 | LTE measurements|
41
UE Signal quality – symbolic structure of mobile radio tester MRT Test equipment Rx … … …
DUT
RF correction
l l l l l
IDFT
FFT
… … …
l
TxRx equalizer
Inbandemmissions
Carrier Frequency error EVM (Error Vector Magnitude) Origin offset + IQ offset Unwanted emissions, falling into non allocated resource blocks. Inband transmission Spectrum flatness November 2012 | LTE measurements|
42
EVM meas.
UL Power Control: Overview UL-Power Control is a combination of: l Open-loop:
UE estimates the DL-Pathloss and compensates it for the UL l Closed-loop:
in addition, the eNB controls directly the ULPower through powercontrol commands transmitted on the DL
November 2012 | LTE measurements|
43
PUSCH power control l
Power level [dBm] of PUSCH is calculated every subframe i based on the following formula out of TS 36.213
MPR Maximum allowed UE power in this particular cell, but at maximum +23 dBm1)
Combination of cell- and UE-specific components configured by L3
Number of allocated resource blocks (RB)
Transmit power for PUSCH in subframe i in dBm
Bandwidth factor 1)
Cell-specific parameter configured by L3
PUSCH transport format
Downlink path loss estimate
Power control adjustment derived from TPC command received in subframe (i-4)
Basic open-loop starting point Dynamic offset (closed loop)
+23 dBm is maximum allowed power in LTE according to TS 36.101, corresponding to power class 3bis in WCDMA
November 2012 | LTE measurements|
44
Pcmax definition „lower“ tolerance
„upper“ tolerance
„corrected“ UE power
PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H) PCMAX_L = min{PEMAX_L, PUMAX }
PCMAX_H = min{PEMAX_H, PPowerClass} Max. power permitted in cell
Max. power permitted in cell, considering bandwidth confinement
Max. power for UE
Max. power for UE, considering maximum power reduction
November 2012 | LTE measurements|
45
Pcmax definition PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H), lPCMAX_L = min{PEMAX_L , PUMAX }, l
PEMAX_L is the maximum allowed power for this particular radio cell configured by higher layers and corresponds to P-MAX information element (IE) provided in SIB Type1
l l
PEMAX_L is reduced by 1.5 dB when the transmission BW is confined within FUL_low and FUL_low+4 MHz or FUL_high – 4 MHz and FUL_high, PPowerClass + 2dB
23dBm -1.5dB
PPowerClass - 2dB
-1.5dB
FUL_high- 4MHz
FUL_low November 2012 | LTE measurements|
46
FUL_high
Pcmax definition PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H), PCMAX_L = min{PEMAX_L , PUMAX }, l
PUMAX corresponds to maximum power (depending on power class, taking into account Maximum Power Reduction MPR and additional A-MPR UE may decide to reduce power
UE power class = 23dBm ±2 dB
Network may signal bandwidth restriction NS_0x
November 2012 | LTE measurements|
47
UE Maximum Power Reduction UE transmits at maximum power, maximum allowed TX power reduction is given as
Modulation
Channel bandwidth / Transmission bandwidth configuration [RB]
MPR (dB)
1.4 MHz
3.0 MHz
5 MHz
10 MHz
15 MHz
20 MHz
QPSK
>5
>4
>8
> 12
> 16
> 18
≤1
16 QAM
≤5
≤4
≤8
≤ 12
≤ 16
≤ 18
≤1
16 QAM Full
>5
>4
>8
> 12
> 16
> 18
≤2
Higher order modulation schemes require more dynamic -> UE will slightly repeal its confinement for maximum power November 2012 | LTE measurements|
48
UE Additional Maximum Power Reduction A-MPR Additional maximum power reduction requirements can be signaled by the network as NS value in SIB2
Network Signaling value
Requirements (sub-clause)
E-UTRA Band
Channel Bandwidth (MHz)
Resource Blocks
A-MPR (dB)
NS_01
NA
NA
NA
NA
NA
6.6.2.2.3.1
2,4,35,36
3
>5
≤1
6.6.2.2.3.1
2,4,10,35,36
5
>6
≤1
6.6.2.2.3.1
2,4,10,35,36
10
>6
≤1
6.6.2.2.3.1
2,4,10,35,36
15
>8
≤1
6.6.2.2.3.1
2,4,10,35,36
20
>10
≤1
NS_04
6.6.2.2.3.2
TBD
TBD
TBD
TBD
NS_05
6.6.3.3.3.1
1
10,15,20
≥ 50 for QPSK
≤1
NS_06
6.6.2.2.3.3
12, 13, 14, 17
1.4, 3, 5, 10
n/a
n/a
NS_07
6.6.2.2.3.3 6.6.3.3.3.2
13
10
Table 6.2.4.3-2
Table 6.2.4.3-2
> 29
≤1
> 39
≤2
> 44
≤3
NS_03
(IE AdditionalSpectrumEmission)
NS_08
[NS_09]
6.6.3.3.3.3
19
10, 15
6.6.3.3.3.4
21
TBD
TBD
TBD
-
-
-
-
-
.. NS_32
November 2012 | LTE measurements|
49
PUSCH power control
Transmit output power ( PUMAX), cont’d. 3GPP Band 13 746
756
777
DL
Network Signalling Value
Requiremen ts (sub-clause)
E-UTRA Band
UL
Channel bandwidth (MHz)
Resources Blocks
A-MPR (dB)
…
…
…
…
…
…
NS_07
6.6.2.2.3 6.6.3.3.2
13
10
…
Indicates the lowest RB … … index of transmitted resource blocks
Table 6.2.4 -2
…
l
Table 6.2.4 -2
…
…
Region A 0 – 12
RBStart Defines the length of a contiguous RB allocation
787
Region B
Region C
13 – 18
19 – 42
43 – 49
LCRB [RBs]
6–8
1 – 5 to 9 – 50
≥8
≥18
≤2
A-MPR [dB]
8
12
12
6
3
In case of EUTRA Band 13 depending on RB allocation as well as number of contiguously allocated RB different A-MPR needs to be considered. November 2012 | LTE measurements| 50
Pcmax definition – tolerance values PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H)
Tolerance is depending on power levels
PCMAx (dBm)
Tolerance T(PCMAX) (dB)
21 ≤ PCMAX ≤ 23
2.0
20 ≤ PCMAX < 21
2.5
19 ≤ PCMAX < 20
3.5
18 ≤ PCMAX < 19
4.0
13 ≤ PCMAX < 18
5.0
8 ≤ PCMAX < 13
6.0
-40 ≤ PCMAX < 8
7.0
November 2012 | LTE measurements|
51
Pcmax definition – tolerance values PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H)
PCMAX_H = min{PEMAX_H , PPowerClass }, l
PEMAX_H is the maximum allowed power for this particular radio cell configured by higher layers and corresponds to P-MAX information element (IE) provided in SIB Type 1
UE power class = 23dBm ±2 dB November 2012 | LTE measurements|
52
Pcmax definition – tolerance values PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H)
PCMAX_H = min{PEMAX_H , PPowerClass }, l
PPowerClass. There is just one power class specified for LTE, corresponding to power class 3bis in WCDMA with +23 dBm ± 2dB, MPR and A-MPR are not taken into account,
EUTRA band
Class 1 (dB m)
Tolerance (dB)
Class 2 (dBm)
Tolerance (dB)
Class 3 (dBm )
Tolerance (dB)
1
23
±2
2
23
±22
…
23
±22
40
23
±2
November 2012 | LTE measurements|
53
Class 4 (dBm)
Tolerance (dB)
Pcmax value for power control - analogies PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H) PCMAX_L = min{PEMAX_L, PUMAX }
PCMAX_H = min{PEMAX_H, PPowerClass}
Maximum speed = 280 km/h =PPowerClass
=PEMAX_H
=PEMAX_L
Under those conditions, I shall drive more carefully! Not going to the max seed! -> speed reduction =PUMAX
November 2012 | LTE measurements|
54
LTE RF Testing: UE Maximum Power
UE transmits with 23dBm ±2 dB QPSK modulation is used. All channel bandwidths are tested separately. Max power is for all band classes Test is performed for varios uplink allocations
November 2012 | LTE measurements|
55
RF power
Resource Blocks number and maximum RF power 1 active resource block (RB),
Nominal band width 10 MHz = 50 RB’s
RF power
Frequency
One active resource block (RB) provides maximum absolute RF power More RB’s in use will be at lower RF power in order to create same integrated power
RF power
Frequency
MPR
Additionally, MPR (Max. Power Reduction) and AMPR are defined
Frequency November 2012 | LTE measurements|
56
UE Maximum Output Power – Test Configuration Initial Conditions Test Environment as specified in TS 36.508 subclause 4.1
Normal, TL/VL, TL/VH, TH/VL, TH/VH
Test Frequencies as specified in TS 36.508 subclause 4.3.1
Low range, Mid range, High range
Test Channel Bandwidths as specified in TS 36.508 subclause 4.3.1
Lowest, 5MHz, Highest
Temperature/Voltage high/low
Test Parameters for Channel Bandwidths Downlink Configuration Ch BW
N/A for Max UE output power testing
Uplink Configuration Mod’n
RB allocation FDD
TDD
1.4MHz
QPSK
1
1
1.4MHz
QPSK
5
5
3MHz
QPSK
1
1
3MHz
QPSK
4
4
5MHz
QPSK
1
1
5MHz
QPSK
8
8
10MHz
QPSK
1
1
10MHz
QPSK
12
12
15MHz
QPSK
1
1
15MHz
QPSK
16
16
20MHz
QPSK
1
1
20MHz
QPSK
18
18
November 2012 | LTE measurements|
57
UE maximum power PPowerClass + 2dB
23dBm PPowerClass - 2dB
FUL_low
maximum output power for any transmission bandwidth within the channel bandwidth November 2012 | LTE measurements|
58
FUL_high
UE maximum power – careful at band edge! PPowerClass + 2dB
23dBm PPowerClass - 2dB
-1.5dB
FUL_low
FUL_low+4MHz
FUL_high- 4MHz
-1.5dB
FUL_high
For transmission bandwidths confined within FUL_low and FUL_low + 4 MHz or FUL_high – 4 MHz and FUL_high, the maximum output power requirement is relaxed
by reducing the lower tolerance limit by 1.5 dB November 2012 | LTE measurements|
59
UE maximum power - examples Example 1: No maximum power reduction by higher layers PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H) PCMAX_L = min{PEMAX_L, PUMAX } Max. power permitted in cell, considering bandwidth confinement
Max. power for UE, considering maximum power reduction
PCMAX_H = min{PEMAX_H, PPowerClass} Max. power permitted in cell
Max. power for UE
T(PCMAX_L) = T(PCMAX_H)=2dB PEMAX_L = none PUMAX = power class 3 = +23 dBm PEMAX_H = none PPowerClass = power class 3 = +23 dBm 25dBm PPowerClass + 2dB 23dBm PPowerClass - 2dB
FUL_high
FUL_low November 2012 | LTE measurements|
60
21dBm
UE maximum power - examples Example 2: max cell power = 0 dBm + band edge maximum power reduction PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H) PCMAX_L = min{PEMAX_L, PUMAX }
PEMAX_L = 0dBm -1.5 dB relaxation = -1.5dBm PUMAX = power class 3 – band relaxation = +21.5 dBm
PCMAX_H = min{PEMAX_H, PPowerClass} PEMAX_H = 0 dBm PPowerClass = power class 3 = +23 dBm
PCMAX_L=-1.5dBm
PCMAX_H=0 dBm T(PCMAX_L) = T(PCMAX_H)=7dB PCMAX_H + 7dB
+7dBm 0 dBm
PCMAX_L - 7dB
FUL_low
FUL_high
FUL_low+4MHz November 2012 | LTE measurements|
61
-8.5dBm
UE maximum power - examples Example 3: Band 13 with NS_07 signalled ( = A-MPR). No Max Power restriction 16 QAM, 12 Resource blocks and RB start = 13. Bandwidth = 10 MHz MPR = 1dB, A-MPR = 12 dB, no band edge relaxation
PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H) PCMAX_L = min{PEMAX_L, PUMAX } PEMAX_L = none PUMAX = power class 3 – MPR – A.MPR = +10 dBm PCMAX_L=10 dBm
PCMAX_H = min{PEMAX_H, PPowerClass} PEMAX_H = none PPowerClass = power class 3 = +23 dBm
T(PCMAX_L) = 6 dB T(PCMAX_H)=2dB
PCMAX_H=23 dBm PCMAX_H +2dB
PCMAX_L - 6dB
RB start = 13
FUL_high
12 Resource blocks November 2012 | LTE measurements|
62
+25dBm 23 dBm
4 dBm
UE maximum power - examples Example 4: band edge power relaxation – no higher layer reduction signalled QPSK, 15 RBs allocated, Band 2, RB allocated at band edge MPR = 1dB, A-MPR = 1 dB, band edge relaxation of 1.5dB PCMAX_L– T(PCMAX_L) ≤ PCMAX ≤ PCMAX_H + T(PCMAX_H) PCMAX_H = min{PEMAX_H, PPowerClass}
PCMAX_L = min{PEMAX_L, PUMAX } PEMAX_L =none PUMAX = power class 3 – MPR-A-MPR-band relaxation = 23-1-1-1.5=+19.5 dBm PCMAX_L=19.5dBm
PEMAX_H = none PPowerClass = power class 3 = +23 dBm PCMAX_H= 23 dBm PCMAX_H + 2dB
T(PCMAX_L) = 3.5 dB T(PCMAX_H)=2dB
+25 dBm 23 dBm
PCMAX_L – 3.5 dB
FUL_low
PCMAX_L – 2 dB
+16 dBm
FUL_high
FUL_low+4MHz November 2012 | LTE measurements|
63
LTE RF Testing: UE Minimum Power
UE transmits with -40dBm
All channel bandwidths are tested separately. Minimum power is for all band classes < -39 dBm
November 2012 | LTE measurements|
64
LTE RF Testing: UE Off Power The transmit OFF power is defined as the mean power in a duration of at least one sub-frame (1ms) excluding any transient periods. The transmit OFF power shall not exceed the values specified in table below
Channel bandwidth / Minimum output power / measurement bandwidth
1.4 MHz
3.0 MHz
10 MHz
15 MHz
20 MHz
13.5 MHz
18 MHz
-50 dBm
Transmit OFF power
Measurement bandwidth
5 MHz
1.08 MHz
2.7 MHz
4.5 MHz
November 2012 | LTE measurements|
9.0 MHz
65
Power Control Related test items l Absolute Power Control Tolerance -- PUSCH open loop
power control l Relative Power Control Tolerance – PUSCH relative power
control, including both power ramping and power change due to Ressource block allocation change or TPC commands l Aggregate Power Control – PUSCH and PUCCH power
control ability when RB changes every subframe
November 2012 | LTE measurements|
66
Absolute Power Control Tolerance l The purpose of this test is to verify the UE transmitter’s
ability to set its initial output power to a specific value at the start of a contiguous transmission or non-contiguous transmission with a long transmission gap.
November 2012 | LTE measurements|
67
Power Control - Absolute Power Tolerance l
…. ability to set initial output power to a specific value at the start of a contiguous transmission or non-contiguous transmission with a long transmission gap (>20ms).
l
Set p0-NominalPUSCH to -105 (test point 1) and -93 (test point 2)
l
Test requirement example for test point 1: Channel bandwidth / expected output power (dBm) 1.4 MHz
3.0 MHz
5 MHz
10 MHz
15 MHz
20 MHz
Expected Measured power Normal conditions
-14.8 ± 10.0
-10.8 ± 10.0
-8.6 ± 10.0
-5.6 ± 10.0
-3.9 ± 10.0
-2.6 ± 10.0
Expected Measured power Extreme conditions
-14.8 ± 13.0
-10.8 ± 13.0
-8.6 ± 13.0
-5.6 ± 13.0
-3.9 ± 13.0
-2.6 ± 13.0
November 2012 | LTE measurements|
68
Configured UE transmitted Output Power
IE P-Max (SIB1) = PEMAX
To verify that UE follows rules sent via system information, SIB Test: set P-Max to -10, 10 and 15 dBm, measure PCMAX Channel bandwidth / maximum output power 1.4 MHz
3.0 MHz
5 MHz
10 MHz
PCMAX test point 1
-10 dBm ± 7.7
PCMAX test point 2
10 dBm ± 6.7
PCMAX test point 3
15 dBm ± 5.7
November 2012 | LTE measurements|
69
15 MHz
20 MHz
LTE Power versus time RB allocation is main source for power change
Not scheduled Resource block
PPUSCH (i) min{PMAX ,10 log10 (M PUSCH (i)) PO_PUSCH ( j ) PL TF (TF (i)) f (i)} Bandwidth allocation
Given by higher layers TPC commands or not used
November 2012 | LTE measurements|
70
Accumulative TPC commands
TPC Command Field In DCI format 0/3
Accumulated PUSCH [dB]
0
-1
1
0
2
1
3
3
2
minimum power in LTE
November 2012 | LTE measurements|
71
Absolute TPC commands PPUSCH (i) min{ PMAX ,10 log 10 ( M PUSCH (i)) PO_PUSCH ( j ) PL TF (TF (i)) f (i)}
TPC Command Field In DCI format 0/3
Absolute PUSCH [dB] only DCI format 0
0
-4
1
-1
2
1
3
4
Pm -1 -4
November 2012 | LTE measurements|
72
Relative Power Control Power pattern B
Power pattern A
RB change RB change
0 .. 1
9
sub-frame# 2 3
4
radio frame
Power pattern C
9
sub-frame# 2 3
9
sub-frame# 2 3
4
radio frame
l The purpose of this test is to verify RB change
0 .. 1
0 .. 1
4
radio frame
the ability of the UE transmitter to set its output power relatively to the power in a target sub-frame, relatively to the power of the most recently transmitted reference sub-frame, if the transmission gap between these subframes is ≤ 20 ms.
November 2012 | LTE measurements|
73
Power Control – Relative Power Tolerance l
…. ability to set output power relative to the power in a target sub frame, relative to the power of the most recently transmitted reference sub-frame, if the transmission gap between these sub-frames is ≤ 20 ms.
November 2012 | LTE measurements|
74
Power Control – Relative Power Tolerance l
Various power ramping patterns are defined
ramping down
alternating
ramping up
November 2012 | LTE measurements|
75
UE power measurements – relative power change Power step P (Up or down) [dB]
All combinations of PUSCH and PUCCH transitions [dB]
All combinations of PUSCH/PUCCH and SRS transitions between subframes [dB]
ΔP < 2
±2.5 (Note 3)
±3.0
±2.5
2 ≤ ΔP < 3
±3.0
±4.0
±3.0
3 ≤ ΔP < 4
±3.5
±5.0
±3.5
4 ≤ ΔP ≤ 10
±4.0
±6.0
±4.0
10 ≤ ΔP < 15
±5.0
±8.0
±5.0
15 ≤ ΔP
±6.0
±9.0
±6.0
PRACH [dB]
P
Power tolerance relative given by table time November 2012 | LTE measurements|
76
UE power measurements – relative power change Power
Power
FDD test patterns
0 1
Sub-test
TDD test patterns
9 sub-frame#
Uplink RB allocation
0
TPC command
2 3
7
8
Expected power step size (Up or down)
test for each bandwidth, here 10MHz
9 sub-frame#
Power step size range (Up or down)
PUSCH/
ΔP [dB]
ΔP [dB]
[dB]
1
ΔP < 2
1 ± (1.7)
A
Fixed = 25
Alternating TPC = +/-1dB
B
Alternating 10 and 18
TPC=0dB
2.55
2 ≤ ΔP < 3
2.55 ± (3.7)
C
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)
November 2012 | LTE measurements|
77
UE aggregate power tolerance Aggregate power control tolerance is the ability of a UE to maintain its power in non-contiguous transmission within 21 ms in response to 0 dB TPC commands TPC command
UL channel
Aggregate power tolerance within 21 ms
0 dB
PUCCH
±2.5 dB
0 dB
PUSCH
±3.5 dB
Note: 1. The UE transmission gap is 4 ms. TPC command is transmitted via PDCCH 4 subframes preceding each PUCCH/PUSCH transmission.
Tolerated UE power deviation
P
UE power with TPC = 0
Time = 21 milliseconds November 2012 | LTE measurements|
78
Aggregate Power Control l The purpose of this test is to verify the UE’s ability to
maintain its power level during a non-contiguous transmission within 21 ms in response to 0 dB TPC commands with respect to the first UE transmission, when the power control parameters specified in TS 36.213 are constant. l Both PUSCH mode and PUCCH mode need to be tested Power
Power
FDD test patterns
0 5 sub-frame#
0
5
TDD test patterns
0
3 8 sub-frame#
3
November 2012 | LTE measurements|
8
3
79
UE aggregate power tolerance Power
Power
FDD test patterns
0 5 sub-frame#
0
5
TDD test patterns
0
3 8 sub-frame#
3
8
3
Test performed with scheduling gap of 4 subframes November 2012 | LTE measurements|
80
UE power measurement – timing masks Start Sub-frame
Start of ON power
End sub-frame
End of ON power
End of OFF power requirement
Start of OFF power requirement * The OFF power requirements does not apply for DTX and measurement gaps
20µs
20µs
Transient period
Transient period
Timing definition OFF – ON commands
Timing definition ON – OFF commands November 2012 | LTE measurements|
81
Power dynamics
PUSCH = OFF PUSCH = ON PUSCH = OFF Please note: scheduling cadence for power dynamics November 2012 | LTE measurements|
82
time
General ON/OFF time mask Measured subframe = 2 UL/DL Scheduling should be configured properly. TDD Issues: - Special Subframe Configuration - >off power before is highter than off power after - <> tune down DL power
November 2012 | LTE measurements|
83
PRACH time mask PRACH
ON power requirement End of OFF power requirement
Start of OFF power requirement
20µs
20µs
Transient period
PRACH preamble format
Measurement period (ms)
0
0.9031
1
1.4844
2
1.8031
3
2.2844
4
0.1479
Transient period
Channel bandwidth / Output Power [dBm] / measurement bandwidth
1.4 MHz
3.0 MHz
Transmit OFF power
5 MHz
10 MHz
15 MHz
20 MHz
-48.5 dBm
Transmission OFF Measurement bandwidth
1.08 MHz
2.7 MHz
4.5 MHz
9.0 MHz
13.5 MHz
18 MHz
Expected PRACH Transmission ON Measured power
-1± 7.5
-1 ± 7.5
-1 ± 7.5
-1 ± 7.5
-1 ± 7.5
-1 ± 7.5
November 2012 | LTE measurements|
84
UE power measurement – PRACH timing mask PRACH preamble format
Measurement period (ms)
0
0.9031
1
1.4844
2
1.8031
3
2.2844
4
0.1479
PRACH
ON power requirement End of OFF power requirement
Start of OFF power requirement
20µs
20µs
Transient period
November 2012 | LTE measurements|
Transient period
85
PRACH measurements
For PRACH you have to set a trigger
Reminder: PRACH is CAZAC sequence November 2012 | LTE measurements|
86
PRACH measurement: constellation diagram
Reminder: PRACH is CAZAC sequence
November 2012 | LTE measurements|
87
PRACH measurement: power dynamics
November 2012 | LTE measurements|
88
Sounding Reference Signal Time Mask
November 2012 | LTE measurements|
89
UE power measurement – SRS timing mask SRS SRS ON power requirement
Single Sounding Reference Symbol End of OFF power requirement
Start of OFF power requirement
20µs
20µs
Transient period
SRS
Double Sounding Reference Symbol
Transient period
SRS
SRS ON power requirement
SRS ON power requirement
End of OFF power requirement 20µs
Transient period
Start of OFF power requirement 20µs
20µs
*Transient period
20µs
Transient period
* Transient period is only specifed in the case of frequency hopping or a power change between SRS symbols
November 2012 | LTE measurements|
90
UE power measurement – Subframe / slot boundary N+1 Sub-frame
N0 Sub-frame
Sloti Start of N+1 power requirement
20µs
20µs
Transient period
N+2 Sub-frame
Sloti+1 End of N+1 power requirement
20µs
20µs
20µs
Transient period
Transient period
If intra-slot hopping is enabled Periods where power changes may occur November 2012 | LTE measurements|
20µs
91
Tx power aspects RB power = Ressource Block Power, power of 1 RB TX power = integrated power of all assigned RBs
November 2012 | LTE measurements|
92
Resource allocation versus time PUCCH allocation
No resource scheduled PUSCH allocation, different #RB and RB offset November 2012 | LTE measurements|
93
TTI based scheduling
November 2012 | LTE measurements|
94
LTE scheduling impact on power versus time
TTI based scheduling. Different RB allocation Impact on UE power
November 2012 | LTE measurements|
95
Transmit signal quality
November 2012 | LTE measurements|
96
Transmit signal quality – carrier leakage
Frequency error
fc
f
Fc+ε
Carrier leakage (The IQ origin offset) is an additive sinusoid waveform that has the same frequency as the modulated waveform carrier frequency. Parameters
Relative Limit (dBc)
Output power >0 dBm
-25
-30 dBm ≤ Output power ≤0 dBm
-20
-40 dBm Output power < -30 dBm
-10
November 2012 | LTE measurements|
97
Frequency Error …. ability of both the receiver and the transmitter to process frequencies correctly…
The 20 frequency error Δf results must fulfil this test requirement: |Δf| ≤ (0.1 PPM + 15 Hz) observed over a period of one time slot (0.5ms)
November 2012 | LTE measurements|
98
Impact on Tx modulation accuracy evaluation l
3 modulation accuracy requirements l EVM for the allocated RBs l LO leakage for the centred RBs
! LO spread on all RBs
l I/Q imbalance in the image RBs LO leakage level
RF carrier
signal
I/Q imbalance
noise
RB0
RB1
RB2
RB3
RB4
EVM
November 2012 | LTE measurements|
99
RB5
frequency
Inband emissions 3 types of inband emissions: general, DC and IQ image
Used allocation < ½ channel bandwidth
channel bandwidth November 2012 | LTE measurements|
100
Carrier Leakage Carrier leakage (the I/Q origin offset) is a form of interference caused by crosstalk or DC offset. It expresses itself as an un-modulated sine wave with the carrier frequency. I/Q origin offset interferes with the center sub carriers of the UE under test. The purpose of this test is to evaluate the UE transmitter to verify its modulation quality in terms of carrier leakage.
DC carrier leakage due to IQ offset
LO Leakage
Parameters
Relative Limit (dBc)
Output power >0 dBm
-25
-30 dBm ≤ Output power ≤0 dBm
-20
-40 dBm Output power < -30 dBm
-10
November 2012 | LTE measurements|
101
Inband emmission – error cases
November 2012 | LTE measurements|
102
DC carrier leakage due to IQ offset
Inband emmission – error cases Inband image due to IQ inbalance
November 2012 | LTE measurements|
103
Inband emmission – error cases Inband image due to IQ inbalance
November 2012 | LTE measurements|
104
DC leakage and IQ imbalance in real world …
November 2012 | LTE measurements|
105
UL Modulation quality: Constellation diagram LTE PUSCH uses QPSK, 16QAM and 64 QAM (optional) modulation schemes. In UL there is only 1 scheme allowed per subframe
November 2012 | LTE measurements|
106
Error Vector Magnitude, EVM Q Magnitude Error (IQ error magnitude)
Error Vector Measured Signal Ideal (Reference) Signal
Φ
Phase Error (IQ error phase)
I Reference Waveform Demodulator
011001…
Ideal Modulator
-
Input Signal
Σ
Difference Signal
+ Measured Waveform November 2012 | LTE measurements|
107
Error Vector Magnitude, EVM 7 symbols / slot time
0123456 0123456 0123456 0123456
PUSCH symbol frequency
Demodulation Reference symbol, DMRS
Limit values Unit
Level
QPSK
%
17.5
16QAM
%
12.5
64QAM
%
[tbd]
Parameter
November 2012 | LTE measurements|
108
Error Vector Magnitude, EVM CP center
1 SC-FDMA symbol, including Cyclic Prefix, CP OFDM Symbol Part equal to CP
Cyclic prefix FFT Window size FFT window size depends on channel bandwidth and extended/normal CP length
November 2012 | LTE measurements|
109
Error Vector Magnitude, EVM CP center
1 SC-FDMA symbol, including Cyclic Prefix, CP OFDM Symbol Part equal to CP
Cyclic prefix FFT Window size
FFT window size depends on channel bandwidth and extended/normal CP length Cyclic prefix length
Nominal FFT size
Cyclic prefix for symbols 1 to 6 in FFT samples
EVM window length W
Ratio of W to CP for symbols 1 to 6*
1.4
128
9
[5]
[55.6]
3
256
18
[12]
[66.7]
512
36
[32]
[88.9]
10
1024
72
[66]
[91.7]
15
1536
108
[102]
[94.4]
20
2048
144
[136]
[94.4]
Channel Bandwidt h MHz
N cp for symbol 0
N cp for symbols 1 to 6
5 160
144
* Note: These percentages are informative and apply to symbols 1 through 6. Symbol 0 has a longer CP and therefore a lower percentage.
Table from TS 36.101 for normal CP November 2012 | LTE measurements|
110
FFT window does not capture the full length: OFDM Symbol + CP
EVM measurement according to Spec Test Parameters for Channel Bandwidths Downlink Uplink Configuration Configuration Ch BW N/A for PUSCH EVM Mod’n RB allocation testing FDD TDD 1.4MHz QPSK 6 6 1.4MHz QPSK 1 1 1.4MHz 16QAM 6 6 1.4MHz 16QAM 1 1 3MHz QPSK 15 15 3MHz QPSK 4 4 3MHz 16QAM 15 15 3MHz 16QAM 4 4 5MHz QPSK 25 25 5MHz QPSK 8 8 5MHz 16QAM 25 25 5MHz 16QAM 8 8 10MHz QPSK 50 50 10MHz QPSK 12 12 10MHz 16QAM 50 50 (Note 3) (Note 3) 10MHz 16QAM 12 12 15MHz QPSK 75 75 15MHz QPSK 16 16 15MHz 16QAM 75 75 (Note 3) (Note 3) 15MHz 16QAM 16 16 20MHz QPSK 100 100 20MHz QPSK 18 18 20MHz 16QAM 100 100 (Note 3) (Note 3) 20MHz 16QAM 18 18 Note 1: Test Channel Bandwidths are checked separately for each EUTRA band, which applicable channel bandwidths are specified in Table 5.4.2.1-1. Note 2: For partial RB allocation, the starting resource block shall be RB #0 and RB# (max+1 - RB allocation) of the channel bandwidth. November 2012 | LTE measurements| 111 Note 3: Applies only for UE-Categories 2-5
l Applies to PUSCH, PUCCH
and PRACH l PUSCH and PUCCH UL Tx Pwer l @ Max & -36.8 dBm
l PRACH UL Tx Power l FDD: @ -31 dBm & 14 dBm* l TDD: @ -39 dBm & 6 dBm
* 20MHz, we can only reach 13 dBm
Cyclic prefix aspects We can observe a phase shift
CP part
CP
OFDM symbol n-1 Content is different in each OFDM symbol
CP part
CP
OFDM symbol n OFDM symbol is periodic! Cyclic prefix does not provoque phase shift November 2012 | LTE measurements|
112
Time windowing 1 SC-FDMA symbol, including Cyclic Prefix, CP
1 SC-FDMA symbol, including Cyclic Prefix, CP
Cyclic prefix
OFDM Symbol Cyclic Part equal prefix to CP
OFDM Symbol Part equal to CP
Continuous phase shift Difference in phase shift
Phase shift between SC-FDMA symbols will cause side lobes in spectrum display!
November 2012 | LTE measurements|
113
Time windowing
Tx time window creates some kind of clipping in symbol transitions
Tx Time window
Tx Time window Cyclic prefix
OFDM Symbol Cyclic Part equal prefix to CP
OFDM Symbol Part equal to CP
Continuous phase shift
Difference in phase shift
Tx time window can be used to shape the Tx spectrum in a more steep way, but ….
November 2012 | LTE measurements|
114
Time windowing
Tx time window creates some kind of clipping in symbol transitions
Tx Time window
Tx Time window Cyclic prefix
OFDM Symbol Cyclic Part equal prefix to CP
OFDM Symbol Part equal to CP
Continuous phase shift
Difference in phase shift
Tx time window will create a higher Error Vector Magnitude! Here the Tx time window of 5µsec causes Some mismatch between the 2 EVM Measurements of the first SC-FDMA symbol
November 2012 | LTE measurements|
115
EVM vs. subcarrier Nominal subcarriers Each subcarrier Modulated with e.g. QPSK
f f0
f1
f2
f3 Error vector
....
Error vector
Note: simplified figure: in reality you compare the waveforms due to SC-FDMA November 2012 | LTE measurements|
116
Integration of all Error Vectors to Display EVM curve
EVM vs. subcarrier
November 2012 | LTE measurements|
117
EVM Equalizer Spectrum Flatness The EVM equalizer spectrum flatness is defined as the variation in dB of the equalizer coefficients generated by the EVM measurement process. The EVM equalizer spectrum flatness requirement does not limit the correction applied to the signal in the EVM measurement process but for the EVM result to be valid, the equalizer correction that was applied must meet the EVM equalizer spectral flatness minimum requirements. Nominal subcarriers
Amplitude Equalizer coefficients
f f0
f1
Integration of all amplitude equalizer coefficients to display spectral flatness curve
f2
f3
Subcarriers before equalization
1 | A( EC ( f )) |2 12 * N RB 12* N RB P( f ) 10 * log | A( EC ( f ) |2 November 2012 | LTE measurements|
118
Equalization 1-tap equalization = Interpreting the frequency Selectivity as scalar factor
Equalizer tries to set same power level for all subcarriers
A(f) 1-tap equalization = Calculating scalar to amplify or attenuate
f
November 2012 | LTE measurements|
119
Spectrum flatness calculation 1-tap equalization = Interpreting the frequency Selectivity as scalar factor
Equalizer tries to set same power level for all subcarriers
A(f) 1 | A( EC ( f )) |2 12 * N RB 12* N RB P( f ) 10 * log | A( EC ( f ) |2
1-tap equalization = Calculating scalar to amplify or attenuate
f
November 2012 | LTE measurements|
120
Spectral flatness
November 2012 | LTE measurements|
121
Spectrum Flatness Maximum Ripple [dB] Frequency Range FUL_Meas – FUL_Low ≥ 3 MHz and FUL_High – FUL_Meas ≥ 3 MHz 5.4 (p-p) (Range 1) FUL_Meas – FUL_Low < 3 MHz or FUL_High – FUL_Meas < 3 MHz 9.4 (p-p) (Range 2) Note 1: FUL_Meas refers to the sub-carrier frequency for which the equalizer coefficient is evaluated Note 2: FUL_Low and FUL_High refer to each E-UTRA frequency band specified in Table 5.2-1
< 5.4(5.4) dBp-p
< 9.4(13.4) dBp-p max(Range 2)-min(Range 1) < 8.4(11.4) dB
max(Range 1)-min(Range 2) < 6.4(7.4) dB
Range 1
Range 2
FUL_High – 3(5) MHz
November 2012 | LTE measurements|
FUL_High
122
Output RF Spectrum Emissions Out-of-band emissions
occupied bandwidth
Spurious Emissions
Spectrum Emission Mask – SEM -> measurement point by point (RBW) Adjacent Channel Leakage Ratio – ACLR -> integration (channel bandwidth) Spurious domain
ΔfOOB
Channel bandwidth
ΔfOOB
Spurious domain
RB
E-UTRA Band
Worst case: Resource Blocks allocated at channel edge
Harmonics, parasitic emissions, intermodulation and frequency conversion
from modulation process
November 2012 | LTE measurements|
123
Impact on SEM definition l l
SEM defined for worst case scenario: RBs allocated at channel edge OOB emission scales with channel BW >> a SEM per channel BW configuration
5 MHz QPSK LTE Tx spectrum : +23.0 dBm / +22.0 dBm 30
20
1 RB MPR 0dB 5 RBs MPR 0dB 6 RBs MPR 0dB 7 RBs MPR 0dB 8 RBs MPR 0dB 9 RBs MPR 1dB 10 RBs MPR 1dB 11 RBs MPR 1dB 12 RBs MPR 1dB 13 RBs MPR 1dB 14 RBs MPR 1dB 15 RBs MPR 1dB 16 RBs MPR 1dB 18 RBs MPR 1dB 20 RBs MPR 1dB 25 RBs MPR 1dB
10
level (dBm/100kHz)
0
-10
-20
-30
-40
Channel bandwidth 1.4 BWChannel [MHz] Length of OOB domain on one 5 side [MHz]
-50
-60 -10
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
offset (MHz)
November 2012 | LTE measurements|
124
3
5
10
15 20
6
10
15
20 25
Adjacent Channel Leakage Ratio - ACLR The purpose of this test is to verify that the UE transmitter does not cause unacceptable interference to adjacent channels. This is accomplished by determining the adjacent channel leakage [power] ratio (ACLR).
l l l
UTRA ACLR 1+2 EUTRA ACLR EUTRA measured with rectangular filter, WCDMA measured with RRC filter ΔfOOB
E-UTRA channel Channel
E-UTRAACLR1
UTRA ACLR2
UTRAACLR1
RB
November 2012 | LTE measurements|
125
Adjacent Channel Leakage Ratio, ACLR Active LTE carrier, 20MHz BW
1 adjacent LTE carrier, 20MHz BW
2 adjacent WCDMA carriers, 5MHz BW
November 2012 | LTE measurements|
126
Occupied Bandwidth - OBW Occupied bandwidth is defined as the bandwidth containing 99 % of the total integrated mean power of the transmitted spectrum
99% of mean power
Channel Bandwidth [MHz] Transmission Bandwidth Configuration [RB]
Channel edge
Resource block
Channel edge
Transmission Bandwidth [RB]
Active Resource Blocks
DC carrier (downlink only)
November 2012 | LTE measurements|
127
Spectrum Emission Mask, SEM OBW: Occupied bandwidth, defined as 99% of mean power SEM: Spectrum ‚Emission Mask, measured with different resolution bandwidth, 1 MHz or 30 kHz RBW
99% of mean power
1 MHz RBW 30 kHz RBW
November 2012 | LTE measurements|
128
Impact on SEM limit definition Limits depend on channel bandwidth Spectrum emission limit (dBm)/ Channel bandwidth
Limits vary dependent on offset from assigned BW
ΔfOOB (MHz)
1.4 MH z
3.0 M Hz
5 M Hz
10 M Hz
15 M Hz
20 M Hz
Measurement bandwidth
0-1
-10
-13
-15
-18
-20
-21
30 kHz
1-2.5
-10
-10
-10
-10
-10
-10
1 MHz
2.5-5
-25
-10
-10
-10
-10
-10
1 MHz
-25
-13
-13
-13
-13
1 MHz
-25
-13
-13
-13
1 MHz
-25
-13
-13
1 MHz
-25
-13
1 MHz
-25
1 MHz
5-6 6-10
10-15 15-20 20-25
November 2012 | LTE measurements|
129
SEM definition depends on band Spectrum emission mask depends on additionally signalled band values NS_0x Spectrum emission limit (dBm)/ Channel bandwidth ΔfOOB (MHz)
1.4 MHz
3.0 MHz
5 MHz
10 MHz
Measurement bandwidth
0-0.1
-13
-13
-15
-18
30 kHz
0.1-1
-13
-13
-13
-13
100 kHz
1-2.5
-13
-13
-13
-13
1 MHz
2.5-5
-25
-13
-13
-13
1 MHz
-25
-13
-13
1 MHz
-25
-13
1 MHz
-25
1 MHz
5-6
6-10 10-15
e.g. NS_07 =band 13
November 2012 | LTE measurements|
130
Transmitter Spurious Emissions …to verify that UE transmitter does not cause unacceptable interference to other channels or other systems in terms of transmitter spurious emissions. The spurious emission limits apply for the frequency ranges that are more than ΔfOOB (MHz) from the edge of the channel bandwidth
Frequency Range
Maximum Level
Measurement Bandwidth
9 kHz f < 150 kHz
-36 dBm
1 kHz
Channel bandwidth
1.4 MHz
3.0 MHz
5 MHz
10 MHz
15 MHz
20 MHz
150 kHz f < 30 MHz
-36 dBm
10 kHz
30 MHz f < 1000 MHz
-36 dBm
100 kHz
ΔfOOB (MHz)
2.8
6
10
15
20
25
1 GHz f < 12.75 GHz
-30 dBm
1 MHz
Spurious domain
ΔfOOB
Channel bandwidth
ΔfOOB
Spurious domain
RB
E-UTRA Band November 2012 | LTE measurements|
131
LTE Uplink: PUCCH Allocation of PUCCH only.
frequency
November 2012 | LTE measurements|
132
PUCCH measurements PUCCH is transmitted on the 2 side parts of the channel bandwidth
November 2012 | LTE measurements|
133
Transmit intermodulation The transmit intermodulation performance is a measure of the capability of the transmitter to inhibit the generation of signals in its non linear elements caused by presence of the wanted signal and an interfering signal reaching the transmitter via the antenna.
User Equipment(s) transmitting in close vicinity of each other can produce intermodulation products, which can fall into the UE, or eNode B receive band as an unwanted interfering signal. The UE intermodulation attenuation is defined by the ratio of the mean power of the wanted signal to the mean power of the intermodulation product when an interfering CW signal is added at a level below the wanted signal at each of the transmitter antenna port with the other antenna port(s) if any is terminated.
BWChannel (UL) Interference Signal Frequency Offset
5MHz 5MHz
10MHz
10MHz 10MHz
15MHz
20MHz
Interference CW Signal Level
15MHz
20MHz
30MHz
20MHz
40MHz
-35dBc
-29dBc
-35dBc
18MHz
18MHz
-40dBc
Intermodulation Product
-29dBc
-35dBc
-29dBc
-35dBc
Measurement bandwidth
4.5MHz
4.5MHz
9.0MHz
9.0MHz
November 2012 | LTE measurements|
-29dBc
13.5MHz 13.5MHz
134
Spurious Emissions The spurious emissions power is the power of emissions generated or amplified in a receiver that appear at the UE antenna connector.
General receiver spurious emission requirements Frequency Band 30MHz f < 1GHz 1GHz f 12.75 GHz
Measurement Bandwidth
Maximum level
100 kHz
-57 dBm
1 MHz
-47 dBm
November 2012 | LTE measurements|
135
SEM – effect of scrambling Scrambling
Modulation mapper
Transform precoder
Resource element mapper
SC-FDMA signal gen.
Constant Bit pattern
Scrambling disabled + constant bit stream
Scrambling should randomize the bit stream
November 2012 | LTE measurements|
136
LTE Receiver Measurements 1 2 3 4 4.1 4.2 4.3 5 6 6.1 7
Reference sensitivity level Maximum input level Adjacent Channel Selectivity (ACS) Blocking characteristics In-band blocking Out-of-band blocking Narrow band blocking Spurious response Intermodulation characteristics Wide band Intermodulation Spurious emissions
November 2012 | LTE measurements|
137
LTE open loop power control and RSRP reporting Pathloss =
System Information: referenceSignalPower [-60 .. 50]dBm
referenceSignalPower - RSRP
UE measures RSRP: Reference Signal Receive Power
PDSCH, PUCCH or SRS receive power at eNodeB UE reports RSRP: back to the eNB
November 2012 | LTE measurements|
UE PDSCH, PUCCH or SRS transmit power at UE
138
Reference Signal Receive Power, RSRP R
R
Entire bandwidth
R
R
Scan over entire bandwidth, RSRP = power of 1 symbol, as mean power
November 2012 | LTE measurements|
139
Received Signal Strength Indicator, RSSI
noise
R
R
Entire bandwidth
interferer R
R
November 2012 | LTE measurements|
140
LTE measurements RSRP = Reference Signal Received Power Definition
Reference signal received power, the mean measured power of the reference symbols during the measurement period.
Applicable for
TBD
E-UTRA Carrier RSSI
Definition
E-UTRA Carrier Received Signal Strength Indicator, comprises the total received wideband power observed by the UE from all sources, including cochannel serving and non-serving cells, adjacent channel interference, thermal noise etc.
Applicable for
TBD
November 2012 | LTE measurements|
141
LTE measurements: RSRQ Reference Signal Received Quality RSRQ =
RSRP RSSI
Definition
Reference Signal Received Quality (RSRQ) is defined as the ratio N×RSRP/(EUTRA carrier RSSI), where N is the number of RB’s of the E-UTRA carrier RSSI measurement bandwidth. The measurements in the numerator and denominator shall be made over the same set of resource blocks. E-UTRA Carrier Received Signal Strength Indicator (RSSI), comprises the linear average of the total received power (in [W]) observed only in OFDM symbols containing reference symbols for antenna port 0, in the measurement bandwidth, over N number of resource blocks by the UE from all sources, including co-channel serving and non-serving cells, adjacent channel interference, thermal noise etc. The reference point for the RSRQ shall be the antenna connector of the UE. If receiver diversity is in use by the UE, the reported value shall not be lower than the corresponding RSRQ of any of the individual diversity branches.
Applicable for
RRC_CONNECTED intra-frequency, RRC_CONNECTED inter-frequency
November 2012 | LTE measurements|
142
RX Measurements – general setup AWGN Blockers Adjacent channels
Receive Sensitivity Tests User definable DL assignment Table (TTI based)
Specifies DL scheduling parameters like RB allocation Modulation, etc. for every TTI (1ms)
Transmit data according to table on PDSCH Use both Rx Antennas
+ Receive feedback on PUSCH or PUCCH
ACK/NACK/DTX Counting
requirements in terms of throughput (BLER) instead of BER November 2012 | LTE measurements|
143
Downlink channel power for Rx tests Physical Channel PBCH
EPRE Ratio
Physical Channel
PBCH_RA = 0 dB
PBCH_RA = A
PBCH
PBCH_RB = 0 dB PSS
PSS_RA = 0 dB
SSS
SSS_RA = 0 dB
PCFICH
PCFICH_RB = 0 dB
PDCCH
PDCCH_RA = 0 dB
PBCH_RB = B
PDCCH_RB = 0 dB PDSCH
PSS
PSS_RA = A
SSS
SSS_RA = A
PCFICH
PCFICH_RB = B
PDCCH
PDCCH_RA = A PDCCH_RB = B
PDSCH_RA = 0 dB PDSCH PDSCH_RB = 0 dB
PHICH
PDSCH_RA = A
PDSCH_RB = B PHICH
PHICH_RB = 0 dB
For tests where no Ref. Signal boosting is applied
EPRE Ratio
PHICH_RB = B
For tests where Ref. Signal boosting is applied, e.g. ρA = -3dB
November 2012 | LTE measurements|
144
Fixed reference channels Parameter
Unit
Channel bandwidth
MHz
Value 1.4
3
5
10
15
20
Allocated resource blocks
6
15
25
50
75
100
Subcarriers per resource block
12
12
12
12
12
12
Allocated subframes per Radio Frame
10
10
10
10
10
10
QPSK
QPSK
QPSK
QPSK
QPSK
QPSK
1/3
1/3
1/3
1/3
1/3
1/3
8
8
8
8
8
8
1
1
1
1
1
1
Bits
24
24
24
24
24
24
For Sub-Frames 1,2,3,4,6,7,8,9
Bits
1368
3780
6300
13800
20700
27600
For Sub-Frame 5
Bits
n/a
n/a
n/a
n/a
n/a
n/a
For Sub-Frame 0
Bits
528
2940
5460
12960
19860
26760
kbps
341.6
1143.2
1952.8
3952.8
6040.8
7884
1-5
1-5
1-5
1-5
1-5
1-5
Modulation Target Coding Rate Number of HARQ Processes
Processes
Maximum number of HARQ transmissions
Transport block CRC Number of Code Blocks per Sub-Frame (Note 4)
Max. Throughput averaged over 1 frame UE Category
Fixed reference channels defined in TS 36.101 for receiver quality measurements November 2012 | LTE measurements|
145
RX sensitivity level Criterion: throughput shall be > 95% of possible maximum (depend on RMC) Channel bandwidth
E-UTRA Ban d
1.4 MHz (dBm)
3 MHz (dBm)
5 MHz (dBm)
10 MHz (dBm)
15 MHz (dBm)
20 MHz (dBm)
1
-
-
-100
-97
-95.2
-94
FDD
2
-104.2
-100.2
-98
-95
-93.2
-92
FDD
3
-103.2
-99.2
-97
-94
-92.2
-91
FDD
4
-106.2
-102.2
-100
-97
-95.2
-94
FDD
5
-104.2
-100.2
-98
-95
6
-
-
-100
-97
FDD FDD Extract from TS 36.521
Sensitivity depends on band, channel bandwidth and RMC under test November 2012 | LTE measurements|
Duplex Mode
146
Block Error Ratio and Throughput Rx quality
DL signal
Channel setup
Criterion: throughput shall be > 95% of possible maximum (depending on RMC)
November 2012 | LTE measurements|
147
Details LTE FDD signaling Rx Measurements
l
Rx Measurements l
Counting – ACKnowledgement (ACK) – NonACKnowledgement (NACK) – DTX (no answer from UE)
l
Calculating l
l
November 2012 | LTE measurements|
148
BLER (NACK/ALL) Throughput [kbps]
Rx measurements: BLER definition PDCCH, scheduling info
Count #NACKs and calculate BLER
PDSCH, as PRBS
ACK/NACK feedback
Assumption is that eNB Power = UE Rx power
November 2012 | LTE measurements|
149
Rx measurements: BLER definition PDCCH, scheduling info
PDSCH, user data
•ACK = UE properly Receives PDCCH + PDSCH •NACK = UE properly receives PDCCH but does not understand PDSCH •DTX = UE does not understand PDCCH
ACK/NACK feedback
ACK relative = NACK relative = DTX relativ =
# ACK # ACK # NACK # DTX
BLER =
# NACK # ACK # NACK # DTX
# DTX # ACK # NACK # DTX November 2012 | LTE measurements|
150
# NACK # DTX # ACK # NACK # DTX
BLER verification Downlink error insertion to verify the UE reports
November 2012 | LTE measurements|
151
Transportation Block Size Index Transportation block size User data
TBS Idx
FEC
Modulation
0 QPSK
9
Flexible ratio between data and FEC = adaptive coding
16-QAM 15 64-QAM 26
Data rate No change in data rate, but in reliability
S/N November 2012 | LTE measurements|
152
Throughput versus SNR
November 2012 | LTE measurements|
153
UE sensitivity – maximum input level
Maximum input level
Rx Parameter
Units
Channel bandwidth 1.4 MHz
Wanted signal mean power
3
MHz
5 MHz
dBm
November 2012 | LTE measurements|
-25
154
10 MHz
15 MHz
20 MHz
UE sensitivity – RF sensitivity measurement ACK/NACK PRBS minimum input level Channel bandwidth E-UTRA Ban d
1.4 MHz (dBm)
3 MHz (dBm)
5 MHz (dBm)
10 MHz (dBm)
15 MHz (dBm)
20 MHz (dBm)
1
-
-
-100
-97
-95.2
-94
FDD
2
-104.2
-100.2
-98
-95
-93.2
-92
FDD
3
-103.2
-99.2
-97
-94
-92.2
-91
FDD
4
-106.2
-102.2
-100
-97
-95.2
-94
FDD
5
-104.2
-100.2
-98
-95
FDD
6
-
-
-100
-97
FDD
November 2012 | LTE measurements|
155
Duplex Mode
Adjacent Channel Selectivity (ACS) … is a measure of a receiver's ability to receive a E-UTRA signal at its assigned channel frequency in the presence of an adjacent channel signal at a given frequency offset from the centre frequency of the assigned channel and with the given power
Requirement per BW, LTE interferer [1.4MHz]
5MHz
[3MHz]
Padj
ACS= 33dB
ACS= 33dB
Padj = -57.5
Pown= -88.5 Nt= -90.5
Pown= -84.5 Nt= -86.5
2dB IM 1.4MHz LTE 1.4MHz LTE
Pown= -82.3 Nt= -84.3
2dB IM
2dB IM
5MHz LTE
3MHz LTE 3MHz LTE
1.4MHz
3MHz
10MHz
5MHz LTE
5MHz
20MHz
15MHz
= -48.3
Pown= -79.3 Nt= -81.3
Padj
Pown= -77.5 Nt= -79.5
2dB IM
10MHz LTE
5MHz LTE 7.5MHz
Padj,w cdma= -51.3
= -49.5
ACS= 27dB
ACS= 30dB
ACS= 33dB
Padj
= -51.3
= -53.5
ACS= 33dB
Padj
Pow n= -76.3 Nt= -78.3
2dB IM
15MHz LTE
5MHz LTE
20MHz LTE
5MHz LTE 12.5MHz
10MHz
November 2012 | LTE measurements|
2dB IM
156
Adjacent Channel selectivity Adjacent Channel Selectivity (ACS) is a measure of a receiver's ability to receive a E-UTRA signal at its assigned channel frequency in the presence of an adjacent channel signal at a given frequency offset from the centre frequency of the assigned channel and with the given power
Channel bandwidth
Rx Parameter
Units
1.4 MHz
3 MHz
5 MHz
ACS
dB
33.0
33.0
33.0
Rx Parameter
Units
33.0
30
20 MHz 27
Channel bandwidth
1.4 MHz Wanted signal mean power
10 MHz 15 MHz
3 MHz
5 MHz
10 MHz
15 MHz
20 MHz
dBm REFSENS + 14 dB dBm
REFSENS +45.5d B
REFSENS +45.5 dB
REFSENS +45.5dB*
REFSENS +45.5d B
REFSENS +42.5d B
REFSENS +39.5dB
BW Interferer
MHz
1.4
3
5
5
5
5
FInterferer (offset)
MHz
1.4+0.0025 / -1.4-0.0025
3+0.0075 / -3-0.0075
5+0.0025 / -5-0.0025
7.5+0.0075 / -7.5-0.0075
10+0.0125 / -10-0.0125
12.5+0.0025 / -12.5-0.0025
PInterferer
November 2012 | LTE measurements|
157
Receiver performance - Blocking tests In-band blocking Out-of-band blocking Narrow band blocking
5MHz LTE interferer 15MHz below to 15MHz above the UE receive band
CW interferer , more than 15MHz below to 15MHz above the UE receive band
CW interferer at a frequency, which is less than the nominal channel spacing
Throughput shall be ≥ 95%
f >> system bandwidth
fB
November 2012 | LTE measurements|
fc
158
frequency
Spurious Response Spurious response verifies the receiver's ability to receive a wanted signal on its assigned channel frequency without exceeding a given degradation due to the presence of an unwanted CW interfering signal at any other frequency at which a response is obtained i.e. for which the out of band blocking limit as specified in sub-clause 7.6.2 is not met. For Table 7.6.2.3-2 in frequency range 1, 2 and 3, up to
max 24, 6 N RB / 6
exceptions are allowed for spurious response frequencies in each assigned frequency channel when measured using a 1MHz step size, where is the number of resource blocks in the downlink transmission bandwidth configuration (see Figure 5.4.2-1). For these exceptions the requirements of clause 7.7 Spurious Response are applicable. For Table 7.6.2.3-2 in frequency range 4, up to
N RB
max 8, ( N RB 2 LCRBs ) / 8 exceptions are allowed for spurious response frequencies in each assigned frequency channel when measured using a 1MHz step size, where
N RB
is the number of resource blocks in the downlink transmission bandwidth configurations (see Figure 5.4.2-1) and LCRBs is the number of resource blocks allocated in the uplink. For these exceptions the requirements of clause 7.7 Spurious Response are applicable. Out of band blocking Parameter
Units
E-UTRA band PInterferer 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 17, 18, 19, 20, 21, 33,34,35,36,3 7,38,39,40 2, 5, 12, 17
FInterferer (CW)
FInterferer
dBm
Frequency range 1
range 2
range 3
range 4
-44
-30
-15
-15
FDL_low -15 to FDL_low -60
FDL_low -60 to FDL_low -85
FDL_low -85 to 1 MHz
-
FDL_high +15 to FDL_high + 60
FDL_high +60 to FDL_high +85
FDL_high +85 to +12750 MHz
-
-
-
-
FUL_low - FUL_high
MHz
MHz
NOTE: For the UE which supports both Band 11 and Band 21 the out of blocking is FFS.
November 2012 | LTE measurements|
159
Rx quality - Intermodulation Wanted Signal C
Throughput shall be ≥ 95%
Unmodulated Interferer Icw
f
f
Modulated Interferer Imod
fc
fcw
fmod
See TS 36.101 for power and frequency offset definitions
November 2012 | LTE measurements|
160
frequency
CQI reporting ≡CQIn+1
Throughput
Overrated CQI report
high
≡CQIn+2
Optimum throughput if the UE reports CQIn
≡CQIn ≡CQIn-1 ≡CQIn-2
Underrated CQI report low
Prevailing conditions of SIR low
SIR changes, CQI reporting must follow!
SIR
November 2012 | LTE measurements|
161
high
CQI reporting Calculate Median CQI, Evaluate if more than 90% of reported CQI Are in range of median CQI ±1
Network sends median CQI – evaluate BLER on median CQI
BLER on median CQI <= 10% Network sends CQI +1 -> BLER must be > 10%
BLER on median CQI > 10% Network sends CQI -1 -> BLER must be < 10%
November 2012 | LTE measurements|
162
Rx tests – test mode UE
SS ACTIVATE TEST MODE
Test modes defined to perform Rx measurements, loop back possible in test mode
ACTIVATE TEST MODE COMPLETE
UE
SS CLOSE UE TEST LOOP
CLOSE UE TEST LOOP COMPLETE
November 2012 | LTE measurements|
163
UTRAN stack: 2 loop back mode defined Loop back above PDCP, i.e. Layer 2 Packet Data Convergence Protocol PDCP Radio Link Control RLC
Medium Access Control MAC
PHYSICAL LAYER November 2012 | LTE measurements|
164
Test loop mode A UE Test Loop Mode A Function
u0,u u01,u .......u 1 .......u K .................u K -1 N -1
u0,u 1 .......uK -1
User data
User data
Down link
Uplink
UE Test Loop Mode A Function
u0 .. uK -1 ..uN-1 User data
u0...uN -1
u0...uN -1
u0..uK-1
User data
Down link
Uplink November 2012 | LTE measurements|
165
Uplink and downlink may have various capacity
Test loop mode B Loop back above PDCP, i.e. Layer 2
Packet Data Convergence Protocol PDCP PDU size must match
buffer ΔΤ
Delayed loop back November 2012 | LTE measurements|
166
Throughput measurements
Max throughput possible in SISO
November 2012 | LTE measurements|
167
Rx measurements - throughput Throughput Measurement, Settings for max throughput for SISO:
Number of Resource blocks Modulation scheme Transport block size
November 2012 | LTE measurements|
168
LTE Downlink BLER and throughput
Rx quality, Indicating NACKs when Lowering the RS EPRE Of the serving cell.
November 2012 | LTE measurements|
169
Throughput + CQI in LTE Change of RF condition> lower data rate
UE sends different CQI values
November 2012 | LTE measurements|
170
MIMO testing For MIMO, enable cell
One antenna
eNode B Correlation
ReNB 1
Two antennas
ReNB
1
1
Four antennas
ReNB
November 2012 | LTE measurements|
1 4 1 9 9 1 4 19 * 1 9 9 4 * 1 * 1 9 9 1 9 * * 4 1 * 9 9 1
171
MIMO correlation Models from TS 36.521
MIMO in LTE: BLER and throughput
November 2012 | LTE measurements|
172
Throughput measurements
MIMO active, 2 streams with different data rate
November 2012 | LTE measurements|
173
Why do we need fading? l
3GPP specifies various tests under conditions of fading l l l l
WCDMA performance tests HSDPA performance tests LTE performance tests LTE reporting of channel state information tests
See CMW capability lists for details l
Evaluation of MIMO performance gain requires fading l l l
Correlated transmission paths in MIMO connection Simulation of “real life conditions” in the lab Comparison of processing gain for different transmission modes
November 2012 | LTE measurements|
174
Most popular MIMO scheme to increase data rates: Spatial Multiplexing h 11
h 12 TX Ant 1
h22
Space
Matix B
TX Ant 2
d1 LO
d2
h 21
2X2 MIMO
RX Ant 1 RX Ant 2
n1 r1
r2
MIMO RX (e.g. ZF, MMSE,MLD)
Time
n2
No increase of total transmit power, i.e. distribution of transmit power across multiple transmit antennas!
Doubles max. data rates, however, at the expense of SNR @ receiver. Thus, according to Shannon‘s law, decrease of performance. Makes sense for low order modulation schemes only (QPSK, 16QAM), or in case of very good SNR conditions, e.g. for receivers close to base stations.
November 2012 | LTE measurements|
175
de1
de2
How do we test under conditions of fading?
RF
System simulator
Channel emulator Fading Profile
November 2012 | LTE measurements|
176
How do we test under conditions of fading?
System simulator I/Q Interface Option CMW-B510x
IQ Out
IQ In
IQ In
IQ Out
RF
Channel emulator Fading Profile November 2012 | LTE measurements|
177
Internal fading in LTE
November 2012 | LTE measurements|
178
BLER results with and without fading
November 2012 | LTE measurements|
179
Automatic testing: KT100 LTE + internal fading
November 2012 | LTE measurements|
180
Measurement sample (open loop SM)
November 2012 | LTE measurements|
181
BLER vs. SNR Transmit/Receive Diversity
~2dB
AWGN only MCS 7 and 10 Fading EPA 5 Hz Low MCS 7 and 10 ~2dB
November 2012 | LTE measurements|
182
GUI – IP Settings
November 2012 | LTE measurements|
183
LTE E2E using DAU
November 2012 | LTE measurements|
184
LTE E2E using DAU
November 2012 | LTE measurements|
185
Throughput end to end
November 2012 | LTE measurements|
186
End to end testing – ping response, RTT
November 2012 | LTE measurements|
187
What is IMS?
A high level summary l
The success of the internet, using the Internet Protocol (IP) for providing voice, data and media has been the catalyst for the convergence of industries, services, networks and business models, l
l
l
IP provides a platform for network convergence enabling a service provider to offer seamless access to any services, How to merge IP anytime, anywhere, and with any device, and cellular 3GPP has taken these developments into account world?? with specification of IMS,
IMS stands for IP Multimedia Subsystem, l
l
IMS is a global access-independent and standard-based IP connectivity and service control architecture that enables various types of multimedia services to end-users using common internet-based protocols, Defines an architecture for the convergence of audio, video, data and fixed and mobile networks.
November 2012 | LTE measurements|
188
3 GPP System Architecture Evolution Signaling interfaces Data transport interfaces RAN Access PDN directly or via IMS MME UE
PDN
Evolved nodeB
S-GW
P-GW
IMS PSTN
Evolved Packet Core
external
IMS to control access + data transfer
All interfaces are packet switched November 2012 | LTE measurements|
189
IMS Architecture
November 2012 | LTE measurements|
190
IMS protocol structure
user plane
Control plane
SIP/SDP
IKE
Voice video
messaging
RTP
MSRP
UDP / TCP / SCTP IP / IP sec
Layer 3 control
Layer 1/2
Layer 1/2 Mobile com specific protocols
(other IP CAN)
IMS specific protocols
November 2012 | LTE measurements|
192
IMS protocol structure
Media Transport Quality of Service
Signaling H.323 application layer
transport layer
network layer
link layer
Physical layer
Megaco
SIP
RTSP RSVP RTCP
TCP
Media Encap. e.g. H.261, MPEG
RTP
UDP
IPv4, IPv6 e.g. PPP, AAL2/ATM, AAL5/ATM, MAC Sonet, SDH, PDH, Ethernet, RF link = LTE November 2012 | LTE measurements|
193
ISIM: IMS SIM Security keys
Private user ID
Public user ID
Home network ID
PIN
Administrative data
ISIM = application on UICC USIM for LTE access UICC universal integrated circuit card November 2012 | LTE measurements|
194
IMS Registration and Authentication Comparison with LTE
LTE
IMS
ATTACH REQUEST
REGISTER
AUTHENTICATION REQ
401 UNAUTHORIZED
AUTHENTICATION RSP
REGISTER
ATTACH ACCEPT
November 2012 | LTE measurements|
200 OK
195
What is IMS?
Registration with IMS l
l
Prior to IMS registration the UE must discover an IMS entry point (i.e. P-CSCF), which is done through an activation of a PDP context for SIP signaling over 2G (GPRS) or 3G (WCDMA, C2K, EV-DO). Retrieve S-CSCF First, there was SIM (Subscriber Identity user profile Module)…than there was USIM (Universal SIM)…and now there is ISIM (IP Multimedia Service Module), – Public User Identity (identify a user), – Private User Identity (users subscription),
HSS
I-CSCF Retrieve S-CSCF capabilities
Calculate RES, REG request SIP registration request P-CSCF
401 User200 notOK authorized November 2012 | LTE measurements|
196
IMS: SMS over IMS
Message flow for a mobile originated SMS
SIP MESSAGE RP-DATA ( SMS-SUBMIT) SIP 200 OK SIP MESSAGE RP-ACK ( SMS-SUBMIT REPORT) SIP 200 OK
SMS Delivery SIP MESSAGE RP-DATA ( SMS-STATUS REPORT) SIP 200 OK SIP MESSAGE RP-ACK SIP 200 OK
November 2012 | LTE measurements|
197
SMS over IMS
IP based Core Access Network, i.e. EPC
S-CSCF I-CSCF
P-CSCF IP-SM-GW IP short message Gateway to connect S-CSCF to SMS serving centre
November 2012 | LTE measurements|
198
SMS-SC
HSS
LTE Positioning with SUPL 2.0
LTE radio signal
eNB Measurements based on reference sources*
Target Device
Location Server
LPP Assistance data
SUPL enabled Terminal
UE
LPP over RRC Control plane solution
E-SMLC
SET
LPP over SUPL User plane solution
SLP
November 2012 | LTE measurements|
199
Enhanced Serving Mobile Location Center
SUPL location platform
Background for IMS and relation to LTE? l
LTE has been designed as a fully packet-orientated, “all-IP”based, multi-service system with a flat network architecture, l
l
Technical challenges offering circuit-switched services (Voice, SMS) via LTE
3GPP has defined IMS as long-term solution providing circuit-switched services, for the short- / mid-term there is no industry-wide consensus, but different approaches, l
Short-/mid-term: Circuit-switched fallback (CS fallback), – SMS. “SMS over SG”, means SMS via Non-Access Stratum (NAS) signaling, – Voice. Fallback to 3G or 2G technology to take the call,
l
VOLGA – Voice over LTE Generic Access – Call setup time increases while using CS fallback,
l
OneVoice Initiative formed to push for Voice over LTE (VoLTE) based on IMS. November 2012 | LTE measurements|
200
l
How to connect E-UTRAN to CS services? Connection via IMS: 3GPP and OneVoice initiative
First a big mess, Now it seems to be OneVoice l
Voice over LTE Generic Access – VoLGA Forum – interim solution
l
CS Fallback CSFB for voice calls to 2G or 3G services – preferred interim solution
l
Evolved MSC, eMSC – CS Services via EPS – network operator proposal, interim solution
l
SRVCC – Single Radio Voice Call Continuity
l
SV-LTE – simultaneous voice and LTE
l
OTT, Over the top – propietary solution, application based
November 2012 | LTE measurements|
201
IMS: Voice over IMS
Message flow for a mobile originated call INVITE (SDP offer) 183 Session Progress (SDP offer) PRACK 200 OK (PRACK) Resource Reservation
Resource Reservation UPDATE (SDP) 200 OK (UPDATE) (SDP) 180 RINGING PRACK 200 OK (PRACK) 200 OK (INVITE) ACK
November 2012 | LTE measurements|
202
Voice over IMS: IMS call establishment Originating Home Network
UE
P-CSCF
Terminating Network
S-CSCF
1. Invite (Initial SDP Offer) 2. Invite (Initial SDP Offer) 3. Service Control 4. Invite (Initial SDP Offer) 5. Offer Response 6. Offer Response 7. Authorize QoS Resources 8. Offer Response 9. Response Conf (Opt SDP) 10. Resource Reservation
11. Response Conf (Opt SDP) 12. Response Conf (Opt SDP) 13. Conf Ack (Opt SDP) 14. Conf Ack (Opt SDP)
15. Conf Ack (Opt SDP) 16. Reservation Conf 17. Reservation Conf 18. Reservation Conf 19. Reservation Conf 20. Reservation Conf 21. Reservation Conf 22. Ringing 23. Ringing 24. Ringing 26. 200 OK 25. Alert User
27. 200 OK 28. Enabling of Media Flows
29. 200 OK 30. Start Media 31. ACK 32. ACK 33. ACK
November 2012 | LTE measurements|
203
Voice over IMS: IMS protocol profile Adaptive Multirate Codecs are used In VoIP over IMS
Codec mode AMR_12.20 AMR_10.20
Source codec bit-rate 12,20 kbit/s (GSM EFR) 10,20 kbit/s
AMR_7.95
7,95 kbit/s
AMR_7.40
7,40 kbit/s (IS-641)
AMR_6.70
6,70 kbit/s (PDC-EFR)
AMR_5.90
5,90 kbit/s
AMR_5.15
5,15 kbit/s
AMR_4.75
4,75 kbit/s
AMR_SID
1,80 kbit/s (see note 1)
November 2012 | LTE measurements|
204
QoS class identifiers QCI QCI
Priority
Packet Delay Budget
Packet Error Loss Rate
1
2
100 ms
10-2
Conversational Voice
2
4
150 ms
10-3
Conversational Video (Live Streaming)
3
50 ms
10-3
Real Time Gaming
4
5
300 ms
10-6
Non-Conversational Video (Buffered Streaming)
5
1
100 ms
10-6
IMS Signalling
3
Resource Type
GBR
6
6
300 ms
7
7
100 ms
8
8
9
9
10-6
Non-GBR
Example Services
Video (Buffered Streaming) TCP-based (e.g. www, e-mail, chat, ftp, p2p file sharing, progressive video, etc.)
10-3
Voice, Video (Live Streaming), Interactive Gaming
10-6
Video (Buffered Streaming) TCP-based (e.g. www, e-mail, chat, ftp, p2p file sharing, progressive video, etc.)
300 ms
November 2012 | LTE measurements|
205
Voice over LTE – protocol profiles AMR codec
Optimize transmission of Voice by configuring Lower layers Use robust header compression or IP Short PDCP header is used Use RLC in UM mode Small sequence number is used
SRB1 and 2 are supported for DCCH + one UM DRB with QCI 1 for voice for SIP signaling + one AM DRB QCI 5 for SIP signaling + one AM DRB QCI 8 for IMS traffic TTI bundling + DRX to reduce PDCCH Signaling + Semi-persistend scheduling
UDP/ TCP IP Packet Data Convergence PDCP Radio Link Control RLC
Medium Access Control MAC
PHYSICAL LAYER
November 2012 | LTE measurements|
206
IMS: Voice over IMS Interaction with EPS l
Resource reservation (QoS) can be achieved with separate Radio Bearers
SIP QCI = 5 signalling
Voice QCI GBR DRB
QCI = 1
NonGBR
GBR
Default Bearer
Dedicated Bearer
AM DRB
PDCP RLC MAC PHY
UM DRB
Quality of Service Class Indicator Guaranteed Bitrate Data Radio Bearer
November 2012 | LTE measurements|
207
VoLTE connection to CS via IMS CS Connection via Boarder and Media Gateway of IMS Control plane IP based Core Access Network, i.e. EPC
S-CSCF I-CSCF
How to connect VoLTE To legacy network? PSTN CS network
P-CSCF BGW MGCF
BGCF
User plane
MG November 2012 | LTE measurements|
208
HSS
IMS connection to CS services - arguments l
IMS can provide real end-to-end connection
l
IMS defines end-to-end quality of service profiles
l
IMS is completely based on Internet Protocol
l
Supplementary services can be realized
l
Several application servers needed
l
Not widely implemented yet – many operators are reluctant
l
IMS software client needed on UE side
l
What happens under heavy load condition?
November 2012 | LTE measurements|
209
Radio Access Technologies today CDMA2K 1xEVDO
GERAN UTRAN
EUTRAN LTE coverage is not fully up from day one -> interworking with legacy networks is essential!!! November 2012 | LTE measurements|
210
Voice calls in LTE l
There is one common solution: Voice over IMS l
-> also named Voice over LTE VoLTE or OneVoice initiative
But….
What if IMS is not available at first rollout? -> interim solution called Circuit Switched Fallback CSFB = handover to 2G/3G -> or Simultaneous Voice on 1XRTT and LTE, SV-LTE = dual receiver What is if LTE has no full coverage? -> interworking with existing technologies, Single Radio Voice Call Continuity, SRVCC
November 2012 | LTE measurements|
211
2G or 3G CS fallback Voice call E-UTRAN
MME
IMS
Voice over IMS is the solution, but IMS is maybe not available in the first network roll-out. Need for transition solution: Circuit Switched Fall Back, CSFB move the call to 2G or 3G
November 2012 | LTE measurements|
212
2G or 3G CS fallback CS connection as fallback to legacy networks
UE
SGSN GERAN
Voice calls are routed via 2G or 3G
UTRAN MSC
E-UTRAN
MME
Only for signalling
Only packet switched connections
November 2012 | LTE measurements|
213
CSFB issues and questions UTRAN
Target cell assigned or selected by UE? Uu
Iu-ps
SGSN
Gs
Gb GERAN S3
Um
UE
LTE Uu
Iu-cs
MSC Server
A
E-UTRAN
S1-MME
SGs MME
Handover or Redirection?
•Is it a handover command or a command to redirect to a new RAN ? i.e. the UE selects the target cell or the EUTRAN commands the target cell •Is there any information about the target RAN available (SysInfo)? •Is there a packet data connection PDN active or not? •Will the PDN be suspended or continued in the target RAN? •Will the UE re-initiate the PDN or continue? November 2012 | LTE measurements|
214
CS fallback options to UTRAN and GERAN Feature group index, UE indicates CSFB support
November 2012 | LTE measurements|
215
CS fallback to 1xRTT 1xCS CSFB UE
1xRTT CS Access
1xRTT MSC
A1 A1
Tunneling of messages between 1xRTT MSC and UE
1xCS IWS S102 MME
S1-MME 1xCS CSFB UE
S11 Serving/PDN GW
E-UTRAN S1-U
Tunnelled 1xRTT messages
November 2012 | LTE measurements|
216
S102 is the reference point between MME and 1xCS interworking solution SGi
CS fallback to 1xRTT
November 2012 | LTE measurements|
217
CS fallback - arguments l
E-UTRAN and GERAN/UTRAN coverage must overlap
l
No E-UTRAN usage for voice
l
No changes on EPS network required
l
Gs interface MSC-SGSN not widely implemented
l
Increased call setup time
l
No simultaneous voice + data if 2G network/UE does not support DTM
l
SMS can be used without CS fallback, via E-UTRAN
November 2012 | LTE measurements|
218
Why not CSFB? l
Call setup delay
l
Call drop due to handover l
Blind hand-over is used for CSFB
l
Data applications are interupted
l
Legacy RAN coverage needed
November 2012 | LTE measurements|
219
Dual receiver 1xCSFB UE
Circuit switched 1xRTT registration CDMA2000 cell eNB for LTE Packet switched EUTRAN registration
Dual receiver 1xCSFB UEs can handle separate mobility and registration procedures 2 radio links at the same time. UE is registered to 2 networks, no coordination required. When CS connection in 1xRTT, dual receiver UE leaves EUTRAN! November 2012 | LTE measurements|
220
SV-LTE: Simultaneous CDMA200 + LTE
UE
Circuit switched 1xRTT connection CDMA2000 cell eNB for LTE Packet switched EUTRAN connection
Simultaneous Voice UEs can handle 2 radio links at the same time. UE is registered to MME and CDMA2K independently
November 2012 | LTE measurements|
221
OTT – over the top
EUTRAN
Application UE
Evolved nodeB
S-GW
P-GW
PDN
Evolved Packet Core Voice call as application, e.g. Skype, Google talk, … November 2012 | LTE measurements|
222
OTT – over the top - arguments EUTRAN
UE
Application Evolved nodeB
S-GW
P-GW
PDN
Evolved Packet Core
•Propietary solution, needs to be implemented in UE and AS
•Already implemented in computer networks – known application •Support has to be accepted by operator •No Inter-RAT handover is possible November 2012 | LTE measurements|
223
SMS transfer in LTE Encapsulate SMS in NAS Control message-> SMS over SG EMM
Send SMS over IMS Using IP protocol SMS over IMS ESM
User plane
Radio Resource Control RRC
Control & Measurements
Packet Data Convergence PDCP
Radio Bearer
Radio Link Control RLC Logical channels Medium Access Control MAC
Transport channels PHYSICAL LAYER
November 2012 | LTE measurements|
224
CSFB circuit switched fallback – SMS transfer Iu-ps UTRAN
SMS-SC
SGSN
Gs Gb Uu
GERAN S3
Um
MSC Server
A
LTE-Uu UE
Iu-cs
SGs
S1-MME E-UTRAN
For 1xRTT it is the S102 interface
MME
SMS transfer between SMS-SC and MME via new interface SGs. New protocol SGs interface application protocol November 2012 | LTE measurements|
SGsAP
SGsAP
SCTP
SCTP
IP
IP
L2
L2
L1
L1
MME
225
SGs
MSC Server
CSFB circuit switched fallback – SMS transfer SGs interface MS/UE
eNodeB
MME
MSC/VLR
HLR/HSS
1. EPS/IMSI attach procedure
SMS-SMS GMSC
SC
2. Message transfer 3. Send Routeing Info For Short Message
5. Paging 7. Paging
4. Forward Short Message
6. Paging
8. Service Request 9b. Downlink NAS Transport 9c. Uplink NAS Transport 10. Uplink NAS Transport
8a. Service Request
No real fallback, because SMS is sent over NAS signaling
9a. Downlink Unitdata 9d. Uplink Unitdata 11. Uplink Unitdata 12. Delivery report
15. Downlink NAS Transport
13. Delivery report
14. Downlink Unitdata 16. Release Request
Mobile terminated SMS in idle mode, SMS over SG November 2012 | LTE measurements|
226
CSFB circuit switched fallback – SMS transfer l SMS can be transferred in the signaling messages
-> so no real circuit switched fallback l CSFB ready at LTE launch? CSFB needs SGs
interface between MME and MSC l Roaming: no guarantee that CSFB is supported
worldwide l Specification issues: Not clear what happens if
SMS transfer occurs at ongoing CSFB procedure l Test scenarios: No CSFB SMS test scenarios
defined yet November 2012 | LTE measurements|
227
Single Radio Voice Call Continuity Problem: in first network roll-out, there is no full LTE coverage. How to keep call active? => SRVCC
November 2012 | LTE measurements|
228
SRVCC – Single Radio Voice Call Continuity SGSN GERAN
UE
Handover of voice call to 2G or 3G
UTRAN MSC
E-UTRAN
MME
User plane after handover User plane before handover November 2012 | LTE measurements|
IMS
SRVCC is handover from EUTRAN to 2G/3G if no LTE coverage 229
Single Radio Voice Call Continuity UE
E-UTRAN
MME
MSC Server
Target UTRAN/GERAN
Measurement Reports Handover to UTRAN/GERAN required
Initiates SRVCC for voice component Handles PS-PS HO for non-voice if needed
Handover CMD
To eUTRAN Coordinates SRVCC and PS HO response
CS handover preparation IMS Service Continuity Procedure
PS HO response to MME (CS resources)
Handover execution
November 2012 | LTE measurements|
230
3GPP IMS
Single Radio Voice Call Continuity VoLTE call
eNodeB = EUTRAN Handover to UTRAN
VoIP in PS mode
NodeB = UTRAN
Radio Bearer reconfiguration: PS to CS mode time
NodeB = UTRAN
Voice call in CS mode
November 2012 | LTE measurements|
231
l
Handover requirements l
Goal is to have seamless service continuity between LTE and other Legacy Technologies (CDMA2000, WCDMA, GSM)
Data and Voice services l l l l l
Support of all frequency bands and a single radio solution Transparent signaling to allow an independent protocol evolution for both access systems Impact to QoS, e.g. service interruption, should be minimized RAT change procedure shall limit interruption time to less than 300ms 3GPP changes – Ability to tunnel signaling messages between E-UTRAN and 3GPP2 – Support measurements of 3GPP2 channels from E-UTRAN – Capability to trigger a handover to a 3GPP2 system
l
3GPP2 changes – Minimal impact on today’s available cdma2000, Rev. 0 or Rev. A access terminal – Minimal impact to legacy, deployed cdma2000 radio access networks – Influence on circuit switched core network should be minimized
November 2012 | LTE measurements|
232
Handovers?? l
What is : l
Intra-Frequency – Changing between cells on same frequency -> different cell ID
l
Inter-Frequency – Changing between cells on differenct frequency
l
Intra-Band – Changing between cells inside the same band
l
Inter-Band – Changing between cells in different bands
l
Inter-RAT – Changing between cells using different RAT (LTE-WCDMA, LTE-GSM, etc.)
November 2012 | LTE measurements|
233
Handover – what to discuss? UE reads SysInfo
GERAN cell(s)?
eNodeB EUTRAN cell
UTRAN cell(s)? CDMA2K cell(s)? UE Will the UE initiate the change? -> re-selection Will the network initiate the change? -> redirection or handover
NW sends Redirection command? SysInfo of Target?
Handover command?
November 2012 | LTE measurements|
Mandatory for UE supporting CSFB
234
Handover aspects – what to discuss? l
Some keywords that appear – and to be clarified in next slides:
l
Handover? Cell reselection? Cell change order? Redirection? Network assisted cell change, NACC? Circuit switched fallback, CS fallback?
l
l l l l
November 2012 | LTE measurements|
235
Mobility aspects – support from UE l
There are some UE feature groups defined. The UE reports this in the attach procedure to the network: – A. in idle – B.
Support of measurements and cell reselection procedure mode Support of RRC release with redirection procedure in
connected – C.
mode
Support of Network Assisted Cell Change in connected
mode – D.
Support of measurements and reporting in connected
mode – E.
Support of handover procedure in connected mode November 2012 | LTE measurements|
236
Mobility aspects – support from UE Feature
GERAN
UTRAN
HRPD
1xRTT
EUTRAN
A. Measurements and cell reselection procedure in E-UTRA idle mode
Supported if GERAN band support is indicated
Supported if UTRAN band support is indicated
Supported if CDMA200 0 HRPD band support is indicated
Supported if CDMA200 0 1xRTT band support is indicated
Supported for supported bands
B. RRC release with blind redirection procedure in E-UTRA connected mode
Supported if GERAN band support is indicated
Supported if UTRAN band support is indicated
Supported if CDMA200 0 HRPD band support is indicated
Supported if CDMA200 0 1xRTT band support is indicated
Supported for supported bands
C. Cell Change Order (with or without) Network Assisted Cell Change) in EUTRA connected mode
Group 10
N.A.
N.A
N.A
N.A.
D. Inter-frequency/RAT measurements, reporting and measurement reporting event B2 (for inter-RAT) in E-UTRA connected mode
Group 23
Group 22
Group 26
Group 24
Group 25
E. Inter-frequency/RAT handover procedure in E-UTRA connected mode
Group 9 (GSM_conn ected handover) Separate UE capability bit defined in TS 36.306 for PS handover
Group 8 (PS handover) or Group 27 (SRVCC handover)
Group 12
Group 11
Group 13
Table from TS36.331 November 2012 | LTE measurements|
237
LTE Radio Resource Control States 1. What about mobility, when UE is in IDLE state?
Cell search and selection de-allocate Tracking Area ID (TA-ID) and IP address and system information acquisition LTE random access procedure [Initial Access; allocate C-RNTI, TA-ID, IP address]
release of C-RNTI, allocate DRX cycle for PCH
LTE_DETACHED • No IP address assigned, • UE location unknown.
Power-up
LTE_ACTIVE (RRC_CONNECTED) • IP address assigned, • Connected to known cell. OUT_OF_SYNCH
IN_SYNCH
• DL reception possible, • No UL transmission.
• DL reception possible, • UL transmission possible.
© Rohde&Schwarz, 2010
LTE/eHRPD-capable terminal
• IP address assigned, • UE position partially known.
LTE random access procedure [Transition to LTE_ACTIVE state (IN_SYNCH)]
LTE random access procedure [to restore uplink synchronization]
User Equipment (UE)
LTE_IDLE (RRC_IDLE)
2. What about mobility, when UE is in CONNECTED state?
November 2012 | LTE measurements|
238
Mobility between LTE and WCDMA/GSM Radio Access Aspects
GSM_Connected CELL_DCH
Handover
E-UTRA RRC_CONNECTED
Handover GPRS Packet transfer mode
CELL_FACH
CELL_PCH URA_PCH
CCO with optional NACC Reselection Connection establishment/release
Connection establishment/release UTRA_Idle
CCO, Reselection
Reselection
E-UTRA RRC_IDLE
Connection establishment/release
Reselection CCO, Reselection
November 2012 | LTE measurements|
239
GSM_Idle/GPRS Packet_Idle
IRAT Procedures Redirection 1.
UE has an active RF session (EPS Bearer Context, PDP Context)
2.
NW releases RRC connection and indicates target RAT and RF channel in RRC Connection Release Message
3.
UE indicates active PDP Contexts during Routing Area Update procedure on target RAT
4.
NW sets up radio bearer
5.
For WCDMA → LTE redirection can also be signaled in RRC Connection Request
6.
Data connection is interrupted during the procedure
November 2012 | LTE measurements|
240
Redirection AS-security has been activated, and SRB2 with at least one DRB are setup UE
EUTRAN
RRCConnectionRelease
November 2012 | LTE measurements|
241
Redirection to UMTS UE reads SysInfo
eNodeB EUTRAN cell
NodeB(s) UTRAN cell(s) UE will search for suitable cell on UARFCN and initiate CS connection
UE
RRC connection release message with RedirectedCarrierInfo to UTRAN Mandatory for UE supporting CSFB
RRC connection release with redirection without SysInfo November 2012 | LTE measurements|
242
Redirection to UMTS
Rel. 9 feature
UE reads SysInfo
NodeB UTRAN cell
UE will go to indicated cell and initiate CS connection
Sys Info UE
eNodeB EUTRAN cell
RRC connection release message with RedirectedCarrierInfo to UTRAN e-RedirectionUTRA capability is set by UE
RRC connection release with redirection with SysInfo November 2012 | LTE measurements|
243
Redirection to GERAN
eNodeB EUTRAN cell
BTS(s) GSM cell(s) UE will search for suitable cell on ARFCN and initiate CS connection
UE
RRC connection release message with RedirectedCarrierInfo to GSM Mandatory for UE supporting CSFB
RRC connection release with redirection without SysInfo November 2012 | LTE measurements|
244
Redirection to GERAN
Rel. 9 feature
BTS(s) GSM cell(s) UE will go to indicated cell and initiate CS connection
Sys Info UE
eNodeB EUTRAN cell
RRC connection release message with RedirectedCarrierInfo to GSM e-RedirectionUTRA capability is set by UE
RRC connection release with redirection with SysInfo November 2012 | LTE measurements|
245
IRAT Procedures PS Handover l
UE has an active data session (EPS Bearer Context, PDP Context)
l
NW sends handover command e.g. l
l
l
LTE → WCDMA: MobilityFrom EUTRACommand WCDMA → LTE: HandoverFromUTRANCommand_EUTRA
PS radio bearer is immediately setup on target RAT
November 2012 | LTE measurements|
246
Handover (Intra-LTE) AS-security has been activated, and SRB2 with at least one DRB are setup UE
EUTRAN
RRCConnectionReconfiguration
RRCConnectionReconfigurationComplete
November 2012 | LTE measurements|
247
Packet Switched handover to other RAN UE
EUTRAN
MobilityFromEUTRACommand
Contains this information element when Falling back to legacy networks MobilityFromEUTRACommand ::= SEQUENCE { rrc-TransactionIdentifier RRC-TransactionIdentifier, criticalExtensions CHOICE { c1 CHOICE{ mobilityFromEUTRACommand-r8 MobilityFromEUTRACommand-r8-IEs, mobilityFromEUTRACommand-r9 MobilityFromEUTRACommand-r9-IEs, spare2 NULL, spare1 NULL }, criticalExtensionsFuture SEQUENCE {} } }
November 2012 | LTE measurements|
248
Handover (Intra-MME/Serving Gateway) UE
Target eNB
Source eNB
MME
Measurement reporting Handover decision Handover request Admission Control
Handover request Ack RRC connection reconfiguration Detach from old, sync to new cell
Deliver packets to target eNB SN Status Transfer Data forwarding Buffer packets from source eNB
RRC connection reconfiguration complete Path switch Req / Ack UE context release Flush buffer Release resources
November 2012 | LTE measurements|
249
Handover to UMTS: Packet switched handover
eNodeB EUTRAN cell
NodeB(s) UTRAN cell(s) UE UE will select target cell on UARFCN and continue PS connection
MobilityFromEUTRACommand message with purpose indicator = handover to UTRAN EUTRAN contains targetRATmessagecontainer, = Inter-RAT info about target cell
Packet Switched handover to UTRAN November 2012 | LTE measurements|
250
HandoverfromEUTRAN – target RAT message HandoverFromEUTRAN message contains control message of target RAT. Possible messages are: targetRAT-Type geran
Standard to apply
targetRAT-MessageContainer
GSM TS 04.18, or 3GPP TS 44.018
HANDOVER COMMAND
3GPP TS 44.060
PS HANDOVER COMMAND
3GPP TS 44.060
DTM HANDOVER COMMAND
cdma20001XRTT
C.S0001 or later, C.S0007 or later, C.S0008 or later
cdma2000HRPD
C.S0024 or later
utra
3GPP TS 25.331
November 2012 | LTE measurements|
HANDOVER TO UTRAN COMMAND 251
Mobility from EUTRAN – failure case UE
EUTRAN
MobilityFromEUTRACommand
RRC connection re-establishment
Radio link failure in target RAT
UE will try to Reestablish EUTRAN connection
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UE mobility in LTE (RRC CONNECTED state)
Measurement configuration, related RRC messages & information elements RRCConnectionReconfiguration … MeasConfig ...
MeasConfig MeasObjectToAddModList ReportConfigToAddMod QuantityConfig measGapConfig
MeasObjectToAddModList
Neig Cell Info Type of CDMA network (1xRTT, HRPD), CDMA2000 carrier configuration, search window size, cells to add/modify/remove from the neighboring list, cell index (up to 32 cells), PN offset…
… MeasObjectCDMA2000
How? What? When?
Periodic or event (InterRAT: B1, B2) triggered Reporting, hysteresis (0…15 dB), # of cells to report excluding serving cell, report interval (120, …, 10240ms, …, 60 min), time-to-trigger, CDMA2000 threshold (0…63)
ReportConfigToAddMod … ReportConfigInterRAT
measGapConfig Each gap starts at SFN & subframe meeting these conditions : SFN mod T = FLOOR(gapOffset/10) with T = MGRP/10 Subframe = gapOffset mod 10
gp0 (0…39), gp1 (0…79) Two gap pattern 0 and 1, gap length is 6 ms, using two different Transmission Gap Repetition Period of 40 or 80 ms
When to retune the receiver to measure e.g. CDMA2000 or HRPD…
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Inter-RAT Handover to GERAN: cell change order PS connection will be suspended
eNodeB EUTRAN cell
BTS(s) GPRS cell(s) UE will search for suitable cell on ARFCN and re-initiate PS connection
UE
MobilityFromEUTRACommand message with purpose indicator = Cell Change Order to GPRS Mandatory for UE supporting CSFB
Packet Switched cell change order to GPRS without NACC (network assisted cell change) November 2012 | LTE measurements|
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Inter-RAT Handover to GERAN: cell change order PS connection will be suspended
BTS GPRS cell UE will search for suitable cell on ARFCN and initiate PS connection
Sys Info UE
eNodeB EUTRAN cell
MobilityFromEUTRACommand message with purpose indicator = Cell Change Order to GPRS Mandatory for UE supporting CSFB
Packet Switched cell change order to GPRS with NACC (network assisted cell change) November 2012 | LTE measurements|
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Inter-RAT Handover to GERAN: handover PS connection will be handed over
eNodeB EUTRAN cell
BTS GPRS cell UE will search for suitable cell on ARFCN and continue PS connection
UE
MobilityFromEUTRACommand message with purpose indicator = handover to GPRS Mandatory for UE supporting CSFB
Packet Switched handover to GPRS November 2012 | LTE measurements|
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LTE-RTT Handover Circuit Switched Fallback, CSFB
Overview November 2012 | LTE measurements|
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3GPP Changes l
LTE Broadcast Channel l l
l l
l
Tunneling l
l
CDMA System Time 1xEVDO, 1xRTT, WCDMA, GSM cell parameters Cell (re)selection parameters Broadcast as SIB Type 8 or via Dedicated RRC messages
Receiving 1xEVDO overhead messages with dual Rx ATs
Measurement Gaps
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Eg CDMA2000 Changes l
Air interface specification changes l
New protocols defined for – Authentication: EAP-AKA – IP Address Allocation : VSNCP – Multiple PDN support : EMFPA
l l l l
l
Non-optimized and optimized handoff from LTE to eHRPD Preamble Initial Power for handover complete message Handover to 1xEV-DO Rev. B being considered Circuit-Switched Fallback (CS fallback) currently specified in C.S0097-0
Core network changes l
l l
S101 interface – signaling interface S103 interface – bearer interface PDSN extension (now called HSGW) November 2012 | LTE measurements|
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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
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CS fallback to 1xRTT 1xCS CSFB UE
1xRTT CS Access
1xRTT MSC
A1 A1
Tunneling of messages between 1xRTT MSC and UE
1xCS IWS S102 MME
S1-MME 1xCS CSFB UE
S11 Serving/PDN GW
E-UTRAN S1-U
Tunnelled 1xRTT messages
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S102 is the reference point between MME and 1xCS interworking solution SGi
CS fallback to 1xRTT
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CS fallback to 1xRTT CSFB to 1xRTT
MME
CSFB Info
eNodeB EUTRAN cell
1xRTT cell(s)
UE will search for suitable cell on UARFCN and initiate CS connection
UE
RRC connection release message with RedirectedCarrierInfo to Mandatory 1xRTT for UE
Enhancement: UE can pre-register in 1xRTT network
supporting CSFB to 1xRTT
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CS fallback to 1xRTT UE
E-UTRAN
MME
1xCS IWS
1xRTT MSC
UE is EPS attached and registered with 1xRTT CS
UE decision to perform MO call in 1xCS
EXTENDED SERVICE REQUEST (with service type CSFB)
UE CONTEXT MODIFICATION REQUEST (CS Fallback Indicator)
UE CONTEXT MODIFICATION RESPONSE
Optional measurement reports
RRCConnectionRelease with redirection to 1xRTT
UE CONTEXT RELEASE REQUEST Suspend Notification Suspend Acknowledge
UE context release
MO call establishment in 1xRTT network
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S-GW/ P-GW
CS fallback to 1xRTT enhanced 1xCSFB (e1xCSFB) Enhancement: UE can pre-register in 1xRTT network UE
1) Prepare for handover, search for 1xRTT
EUTRAN
HandoverFromEUTRAPreparationRequest
UE
2) Info about 1xRTT -> tunnelled via S102
EUTRAN
ULHandoverPreparationTransfer
UE
3) Includes 1xRTT channel assignment
EUTRAN
MobilityFromEUTRACommand
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Time flow
CS fallback to 1xRTT enhanced 1xCSFB (e1xCSFB) + concurrent HRPD handover Enhancement: UE can pre-register in 1xRTT network
1) Prepare for handover, search for 1xRTT + HRPD
UE
EUTRAN
HandoverFromEUTRAPreparationRequest
2) Trigger 2 messages with info about 1xRTT + HRPD
UE
EUTRAN
ULHandoverPreparationTransfer
UE
EUTRAN
ULHandoverPreparationTransfer
UE
3) Redirection to 1xRTT and handover to HRPD
EUTRAN
MobilityFromEUTRACommand
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Time flow
LTE-eHRPD Handover Overview
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InterRAT Network Architecture Eg CDMA2000 1xEVDO
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EUTRAN – eHRPD non-roaming
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EUTRAN – eHRPD, roaming case
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Mobility between LTE and HRPD Radio Access Aspects
No handover to EUTRAN
HRPD active to EUTRAN is always cell reselection (via RRC idle) November 2012 | LTE measurements|
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3 Step Procedure E-UTRAN needs to decide, that HO to HRPD is required
Ability of preregistration is indicated on PBCCH
UE attached to E-UTRAN
Pre-registration
HO preparation
HO execution
• Reduces time for cell re-selection or handover • Reduces risk of radio link failure Traffic Channel Assignment command is delivered to UE, re-tune radio to HRPD channel, acquire HRPD channel, session configuration
Connection Request issued by UE to HRPD, HRPD prepares for the arrival of the UE
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Video over LTE Testing the next step in the end user experience
Introduction l
Cisco quote 06/2011 l
l
Internet video is now 40 percent of consumer Internet traffic, and will reach 62 percent by the end of 2015, not including the amount of video exchanged through P2P file sharing. The sum of all forms of video (TV, video on demand [VoD], Internet, and P2P) will continue to be approximately 90 percent of global consumer traffic by 2015.
IDC quote 06/2011 l
The fast-growing smartphone market, which will grow more than four times the rate of the overall mobile phone market this year, is being fuelled by falling average selling prices, increased phone functionality, and lower-cost data plans among other factors, which make the devices more accessible to a wider range of users. November 2012 | LTE measurements|
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Introduction Network view
Impact due to EPC / IMS
l Packet delay
l Packet jitter l Packet loss MME
PCRF
l …
Node B SGW
Impact due to
PGW
Internet
l Multipath propagation l Speed l …
Node B
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Introduction
Testing real life conditions in the lab l
Main use cases from a test engineer (operator, manufacturer) perspective: l l l
Exploring the performance of mobile equipment from the end user perspective Measuring E2E throughput with realistic radio conditions Evaluating mobility performance R&S®AMU200 baseband fader simulates real life radio conditions
R&S®CMW500 emulates LTE network
l
CMW-PQA
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Contest SW provides automation and reporting capabilities
Video transmission over LTE Video quality… l
… is the perceived degradation of a processed video in comparison to an ideal reference or the reality
l
… can be used as an evaluation criteria for any kind of video transmission or processing system as signal impairments will happen in different stages
l
… can be categorized in two basic types of video quality assessment l
l
Subjective quality assessment Objective quality assessment
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Video transmission over LTE
The video processing chain and possible sources for video degradation • Encoding artifacts (blocking)
Impairments on the transmission link can cause loss of information despite active error correction
• Video / audio delay • Buffer rules are violated
The decoder is usually the less critical component. But in conjunction with the video processor, errors during the conversion process (e.g. deinterlacing) are possible
Transmission link (IP, cellular, broadcast, etc.) Encoder
TX
RX
Decoder
Receiver
Uncompressed video SDI SMPTE249/292/424
Video processor
Redundant information (static image parts) and irrelevant data (details) is omitted
Restoring the video Scaling and information; i.e. the conversion to output picture sequence format including redundant data
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Output on screen
Video transmission over LTE Subjective quality assessment l
Subjective video quality assessments are defined in ITU-T recommendation BT.500 Mean Opinion Score (MOS)
l
l
Example procedure: A group of trained experts judge the video quality in a scale ranging from bad to excellent. The assessments are averaged and result in to a Mean Opinion Score (MOS).
Advantages: l
l
Subjective assessment provides the best results, as the ultimate measure for video quality is the human eye
Disadvantages: l l
Time consuming and expensive Automation not possible
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MOS
Quality
5
Excellent
4
Good
3
Fair
2
Poor
1
Bad
Video transmission over LTE Objective quality assessment l
Mathematical calculation that approximate averaged results of subjective quality assessment
l
Divided into three categories: l l l
l
Advantage: l
l
Full reference methods (FR) Reduced reference methods (RR) No-reference methods (NR)
Assessment automation is possible for various applications
Disadvantages: l l
Correlation with the actual perceived video quality is not always ensured Many different metrics for specific purposes exist
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Video transmission over LTE
Objective metric – peak signal-to-noise ratio (PSNR) MAX I2 PSNR 10 log10 ( ) MSE 1 m 1 n 1 I (i, j ) K (i, j )2 MSE mn i 0 j 0
l
Most commonly used for quality measurements for image compression.
l
Simple mathematical calculation but poor correlation with subjective methods: l
I(i,j) = original pixel
l
K(i,j) = reconstructed pixel MAX = maximum possible pixel value
l
Digital pixel values do not exactly represent the light stimulus on the human eye The summation is averaging errors without weighting them The same PSNR values may result from different kind of structural errors
Unit: dB Value range: 0 - ∞ dB; the higher, the better
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Video transmission over LTE
Objective metric – structural similarity (SSIM) Signal x
Luminance Measurement
+ Signal y
Contrast Measurement
Luminance Comparison
÷ Luminance Measurement
+ SSIM ( x, y )
Contrast Measurement
Contrast Comparison
l
Improvement to traditional methods for quality measurements to improve consistency with human eye perception.
l
Complex mathematical calculation but fairly good correlation with subjective methods.
Similarity Measure Combination
Structure Comparison
÷ (2 x y C1 )(2 xy C2 )
( x2 y2 C1 )( x2 y2 C2 )
Unit: Value range: 0 - 1; the higher, the better
Reference: Z. Wang, A. C. Bovik, H. R. Sheikh and E. P. Simoncelli, "Image quality assessment: From error visibility to structural similarity," IEEE Transactions on Image Processing, vol. 13, no. 4, pp. 600-612, Apr. 2004.
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Video transmission over LTE
Correlation of objective metric with MOS
(MSSIM = Mean SSIM)
Reference: Z. Wang, A. C. Bovik, H. R. Sheikh and E. P. Simoncelli, "Image quality assessment: From error visibility to structural similarity," IEEE Transactions on Image Processing, vol. 13, no. 4, pp. 600-612, Apr. 2004.
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Video transmission over LTE Metric – visible error l
The shown objective metrics and their correlation with MOS are calculated frame based Temporal masking effects need to be considered: l
Additional condition: e.g. for at least 6 frames SSIM below 0.7 (25 fps video) 1,2 1 0,8 Not visible
SSIM
l
Not visible
0,6
Visible 1 Visible 2
0,4 0,2 6 Frames
Visible Error
0 1
3
5
7
9
11
13
15
17
19
Frame
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21
23
Video transmission over LTE Demo
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Video transmission over LTE Testing real life conditions in the lab
PC Contest TC Control
RF
Video via MHL or HDMI
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Video transmission over LTE R&S®VTE Video Tester l
l
l l
l l
Source, sink and dongle testing on MHL 1.2 interfaces and in the future also HDMI 1.4c, etc. Realtime difference picture analysis for testing video transmissions over LTE Combined protocol testing and audio/video analysis Future-ready, modular platform accommodating up to three test modules Localized touchscreen user interface Integrated test automation and report generation
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R&S®VTE Video Tester
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Video transmission over LTE Mobile high definition link (MHL)
MHL is… l the leading audio/video interface for mobile devices l utilizes the existing Micro-USB connector l provides power to the mobile device l
Single Transition Minimized Differential Signaling (TMDS) channel: l l
l
Single-wire Control Bus (CBUS) l l l
l
Configuration and status exchange Replaces the DDC bus in HDMI Carries the MHL Sideband Channel (MSC) which provides high level control functions
VBUS and associated ground l l
November 2012 | LTE measurements|
Carries video, audio and auxiliary data Bit stream is modulated by a clock signal
Provide power between sink and source 5V, max. 0.5 A 292
Summary l l
Video and voice are important services gaining momentum for the fastest developing radio access technology ever - LTE Beside LTE functionality, testing voice/video quality is essential to judge a good receiver implementation
l R&S provides you with profound expertise and
test solutions on both aspects l Complete LTE test portfolio ranging from early R&D via IOT
and field testing until conformance and production l Supplier of a complete range of TV broadcasting transmission, monitoring and measurement equipment
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There will be enough topics for future trainings
Thank you for your attention! Comments and questions welcome! November 2012 | LTE measurements|
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