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2 MAR | Re |08/00 |
1 GPRS General Packet Radio ServicesGPRS measurements
1MAT 08.10.02
GPRSGeneral Packet Radio Services
(Placeholder for a cover picture; this picture should alwayscover the whole slide width as shown here)
GPRS measurements
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
2
Your Lecturer is:
Reiner StuhlfauthRohde&Schwarz
Training Center, Munich
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
3
Structure of presentation
�GPRS - Test modes
�GPRS - Tx power measurements
�GPRS - modulation measurements
�GPRS - spectrum measurements
�GPRS - Receiver measurements
Outline of Presentation
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
4
GPRS test modesSpecial test mode for GPRSGPRS is a standard for data transfer. Under testing conditions, there is no data source.
MS declaration: 3 classes of MS
Capable to transmit pseudo-random data in RLC data blocks
Capable of transmitting looped-back RLC data blocks
Capable of both
=> There is a special test mode specified in GPRSthat allows the transfer of Pseudo Random Data
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
5
GPRS test modes
Establishment of uplink TBF
Radio Tester orders MS into GPRS test mode, with command: GPRS_TEST_MODE_CMD
=> commands the MS to request uplink resource
Radio Tester orders MS into GPRS test mode, with command: GPRS_TEST_MODE_CMD
=> commands the MS to request uplink resource
PDU Description (12 bit field): Number of PDU’s to transmit in Uplink: 0 .. 4096 PDU’s
PDU Description (12 bit field): Number of PDU’s to transmit in Uplink: 0 .. 4096 PDU’s
Mode Flag M (1 bit field):to select test modes A or B
Mode Flag M (1 bit field):to select test modes A or B
Downlink Timeslot Offset (3 bit field):timeslot offset between uplink and downlink
Downlink Timeslot Offset (3 bit field):timeslot offset between uplink and downlink
Parameters of : GPRS_TEST_MODE_CMD
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
6
GPRS test modes
GSM-RF -physical layerGSM-L2RLCGSM-L3MAC
LLCSNDCP GMM/SN
IPAPP
fast production test mode“reduced signalling”
BLER test modes ETSI 44.014
Signalling test modes for GMSK / 8PSKdefined under ETSI 44.014
Test modes requirefull implementationof certain protocol
layers inside the MS
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
7
GPRS test modes�Test Mode A (GPRS / EGPRS)
ETSI 44.014 test mode commands the mobile into atransmission mode of a PRBS (Pseudo Random Bit Sequence)
����multislot Tx measurements– power versus time– phase and frequency– spectrum (modulation/ switching)
�Test Mode B (GPRS /EGPRS)ETSI 44.014 test mode closes the mobileinternal BER loop for GPRS (CS1-4) andEGPRS (MSC1-9) coded radio blocks
���� Rx measurements:– BER– DBLER– + all Tx measurements
described in Mode A
ETSI 44.014 test modes A and B GSM-RF -physical layer
GSM-L2RLCGSM-L3MAC
LLCSNDCP GMM/SN
IPAPP
For Tx measurementsonly!
For Tx and Rxmeasurements!
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
8
GPRS Tx measurements
GSM 400 and GSM 900 and GSM 850
Powercontrollevel
Nominal Outputpower (dBm)
Tolerance (dB) forconditions
normal extreme
0-2 39 ±2 ±2,53 37 ±3 ±44 35 ±3 ±45 33 ±3 ±46 31 ±3 ±47 29 ±3 ±48 27 ±3 ±49 25 ±3 ±410 23 ±3 ±411 21 ±3 ±412 19 ±3 ±413 17 ±3 ±414 15 ±3 ±415 13 ±3 ±416 11 ±5 ±617 9 ±5 ±618 7 ±5 ±619-31 5 ±5 ±6
GSM 1800
Powercontrollevel
NominalOutput power(dBm)
Tolerance (dB) forconditions
normal extreme
29 36 ±2 ±2,530 34 ±3 ±431 32 ±3 ±40 30 ±3 ±41 28 ±3 ±42 26 ±3 ±43 24 ±3 ±44 22 ±3 ±45 20 ±3 ±46 18 ±3 ±47 16 ±3 ±48 14 ±3 ±49 12 ±4 ±510 10 ±4 ±511 8 ±4 ±512 6 ±4 ±513 4 ±4 ±514 2 ±5 ±615-28 0 ±5 ±6
GSM: Tx Power of MS is ordered via PCL-value
PCL = Power Control Level
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
9
MS-Power in GPRS
PCH = min(Γ0 - ΓCH - α * (C + 48),PMAX)
MS output power is calculated belong formula:
Γ0 = 39dBm for GSM 900 / 400 / 85036 dBm for GSM 1800 / 1900
ΓCH = MS specific parameter, sent in RLC control message, valid per Timeslot, 5 bit value, step of 2 dB from 0..62 dB
α = system parameter on System Information, 4 bit value, from 0.0 .. 1.0 in 10 steps
PMAX = maximum allowed power in that cell
C = received signal level at MS (=RXLEV)
PCH is employed on each individual PDCH !
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
10
MS-Power in GPRS
PCH = min(Γ0 - ΓCH - α * (C + 48),PMAX)
Tx power control settingsimplemented in test equipment
Link adaption parameterαααα is not implemented
in test equipment.Reason is, that MS Tx power
shall be constant
PCH is employed on each individual PDCH !
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
11
GPRS Tx measurementsMultislot MS: Power Measurements
The MS shall use the same output power on all 4 bursts within one radio block
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
Power
time
1 Radio Block
TDMA Frame
Example: Multislot3 Timeslots within 1 TDMA Frame
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
12
GPRS Power measurements
Burst in Timeslot n
PowerRamping
PBurst
Power
TimeTime Start
TimeLength
T=Tail bit F=Flag bit G=Guard Periode
T3
T3
57 Information bits 26 BitsTraining Sequence
F1
F1
G8,25
57 Information bits
Does the burstcorrespond tothe structure?
Points of consideration in Tx measurements
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
13
GPRS Power measurements
dB
t
- 6
- 30
+ 4
8 µs 10 µs 10 µs 8 µs
(147 bits)
7056/13 (542.8) µs 10 µs
(*)
10 µs
- 1+ 1
(***)
(**)
Checking of all the measurements aspects due to power versus time template
specified according to training sequence
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
14
Power versus time single slot
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
15
TS2 TS5TS4TS3
Power versus time “multiburst”
�auto detection of GMSK or 8PSK modulation-> template will be chosen accordingly
�real time positioning of each template section independent (x-axes ref. to mid amble / y-axes ref. to average burst power)
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
16
Power v. time “multiburst” - 2 bursts
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
17
multislot - power v. time “multislot”
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
18
Power v. time - free and easy scaling�the power versus time multislot application offers
� free scaling for time axes– span resolution down to
1 symbol per unit
� free scaling for level axes– span resolution down to
1dB per unit
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
19
Power versus slot
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
20
Gaussian Minimum Shift Keying
Logical 0 = ϕ( bit n+1) - ϕ( bit n ) = 2π
+
Logical 1 = ϕ( bit n+1) - ϕ( bit n ) = 2π
−
I
Q
ϕ(t)
Quadratur component
Inphasecomponent
Q(t)
I(t)
ϕ
cosϕ
sinϕ cos2ϕ + sin2ϕ=1
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
21
Modulation phase + frequency error
Real phase
data
ideal phase
Phase +frequency
error
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
22
Modulation phase + frequency error
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
23
IQ imbalance /origin offset
– I/Q adjustments in CMU works in timedomain (complex base band)independently from the modulationpattern
– origin offset is equivalent to carriersuppressionp(f C+n) - p(f C)
– IQ imbalance is equivalent to sideband suppressionp(f C+n) - p(f C-n)
Q
Iorigin offset
I/Q imbalance
f C-n f C f C+n f C-n f C f C+n
modulation pattern “1” modulation pattern”0”
Used forI/Q
adjustment
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
24
GPRS spectrum measurements
dB
t100%90%Averaging
period
50%midamble
Useful part of the burst
0%
Switching transients
Max-hold level = peak of switching transients
Video average level= spectrum due to
modulation
Spectrum measurement in with RBW=30kHz in zero span with f = fc-1,8MHz, ...fc-0,1MHz, fc, fc-0,1MHZ, fc-0,2MHz, fc-0,4MHz, ...fc+1,8MHz
Spectrum of normal burst in zero span mode with f = fc and RBW = 30kHz
Averaging period for spectrum due tomodulation
Peak detectionfor spectrum
due to switching
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
25
multislot - spectrum due to modulation
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
26
multislot - spectrum due to switching
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
27
GPRS Rx MeasurementsLoop Back Mode in Mobile Station
Burst by burst
DUT
DemodulatorChannel
Decoder
ChannelCoderModulator
RLC/MAC
LayerRAW BERLoop
Loop Back after channelcoding
BER/BLER loop
RAW BER loop
Block by block
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
28
GPRS Rx measurements
RLC DataMACHeader
RLCHeader BCS
Reminder: RLC/MAC block structure in GPRS
Block check sequence protectspayload + header
Header fields are different in
uplink and downlink
Only payload is relevant forBER calculation
Not relevant forBER calculation
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
29
GPRS Rx measurements
BER: Bit Error Rate
DemodulatorChannel
Decoder
Channel
CoderModulatorRLC/MAC
LayerRAW BERLoop
Loop Back after channelcoding
RLC DataMACHeader
RLCHeader BCS
RLC DataMACHeader
RLCHeader BCS
DUT
BER = Received bits in error
Total number of send bits
BER = tester compares sent and received bits of payload
compare
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
30
GPRS Rx measurementsDBLER: Data Block Error Rate
DemodulatorChannel
Decoder
Channel
CoderModulatorRLC/MAC
LayerRAW BERLoop
Loop Back after channelcoding
RLC DataMACHeader
RLCHeader BCS
RLC DataMACHeader
RLCHeader BCS
DUT
DBLER = Received data blocks in error
Total number of send blocks
DBLER = tester compares sent and received payload blocks
compare
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
31
GPRS Rx measurementsUSF-BLER: Uplink State Flag Block Error Rate
n n+1 n+2 n+3 n+4 n+5 n+6
n-2 n-1 n n+2 n+3 n+4
USF valid
USF valid
USF decoding
error
USF valid
USF valid
USF valid
Downlink
Uplink
USF BLER is counting the percentage rate of not received uplink radio blocks
no ULradio block
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
32
GPRS Rx measurementsNegative USF-BLER:
USF invalid
USF invalid
USF decoding
error
USF invalid
USF invalid
USF invalid
Downlink
Uplink
Negative USF BLER is counting the percentage rate of unexpectedly received uplink radio blocks
tester transmits only invalid USF values in downlink
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
33
Test mode B based measurements
number of erroneousreceived UL blocks
CRC error: Cyclic redundancy check error on UL
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
34
Test mode B based measurements
BIT
Gen
erat
ion
GPRSchannelcoder
Modu-lator
De-modu-lator
De-coder
RLC
/MA
C Layer
.... Application Layer
CoderModu-lator
Demodu-lator
GPRSchanneldecoderB
IT
Ana
lysi
s
Ack/Nack
Radio tester GPRS - DUT
TBF for BER Loop“b-mode”
supporting“BER”
“DBLER”“USF BLER”
MS must loop back even in case if BCS detects an Rx error
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
35
�BER�Bit error rate measurement
�USF BLER� indicates the ratio of correct interpreted
UL state flags
�DBLER� indicates the ratio of the correct
received radio blocks
�CRC Err.� indicates errors on the uplink - CRC or
so called BCS (Block Check Sequenz) used to cross check that all BER and DBLER errors are caused on the DL
Test mode B based measurements
CMU200
TBFestablished
via BER Loop“b-mode”
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
36
BLER mode
BIT
Gen
erat
ion
GPRSchannelcoder
Modu-lator
De-modu-lator
De-coder
RLC
/MA
C Layer
.... Application Layer
CoderModu-lator
Demodu-lator
GPRSchanneldecoderB
IT
Ana
lysi
s
Ack/Nack
Radio tester GPRS - DUT
BLER: Block Error Rate
BLER is based on signalling messages
in acknowledgeddata transfer
TBF establishment in RLC acknowledged mode
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
37
BLER example with TBF on 3DL
Mobile
TBF DLBlock 1
Block 2
Block 3
Block 1
Block 2
Block 3
Block 4
Block 5
Block 6
Block 1
Block 2
Block 3
Block 4
Block 5
Block 6
Block 7
Block 8
Block 9
Block 1
Block 2
Block 3
Block 4
Block 5
Block 6
Block 7
Block 8
Block 9
Block10
Block11
Block12
ACK / NACK
Pay load
UL
Radiocom
Tester
TBF establishment via BLER mode
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
38
BLER example with TBF on 3DL
Radiocom
Tester
Mobile
TBF DL
ACK / NACK
Block10
Block 5
Dummy
repeat block 5 and 10 UL
TBF establishment via BLER mode
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
39
Mobile
TBF DLBlock13
Block14
Block15
Block13
Block14
Block15
Block16
Block17
Block18
Block13
Block14
Block15
Block16
Block17
Block18
Block19
Block20
Block21
Block13
Block14
Block15
Block16
Block17
Block18
Block19
Block20
Block21
Block22
Block23
Block24
ACK / NACK
New pay load
BLER example with TBF on 3DL
Radiocom
Tester
UL
TBF establishment via BLER mode
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
40
BLER mode based measurements
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
41
BLER mode based measurements
�sensitivity measurements are done in the so-called “knee” of the BER function
-40 dBm -100 dBmReceiverinput level
BER
a small difference in levelcauses a large change inyour result
=> due to retransmission of erroneous blocks, the execution time for BLER measurement
will enlarge dramatically
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
42
GPRS Rx measurementsWait for next radio
block
Block_Counterall++
Any radioblock
received?
Are all BCSin radio block
correct?
USF_Error_Counter++
RLC_Block_CounterRX++
do BER calcualtion
BCS_Error_Counter++
Is BER >0%?
DBLER_Counter++
Is BER <25%?
BER_Counter :=BER_Counter + Biterrors;RLC_Block_CounterBER++;
NO
NO
NO
YES
YES
NO
YES
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
43
GPRS Rx measurementsRelationship between BLER and DBLER for CS-4
relationship between BLER and DBLER allows thefaster measurement of DBLER instead of BLER
GPRS General Packet Radio ServicesGPRS measurements
1MAT | 08.10.02 |
GPRStest modes
GPRS Txmeasurements
GPRS modulationmeasurements
GPRS spectrummeasurements
GPRS Rxmeasurements
44
Thank you for your attention
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