3g drive test learning
TRANSCRIPT
![Page 1: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/1.jpg)
WCDMA Introduction and Overview
• WCDMA concept and Architecture• Spreading and Scrambling• Codes and Channels• Code tree• Rake Receiver• Soft, Softer and Hard hand over• Power control - fast and slow
WCDMA – Drive test Overview using TEMS Investigation
• TEMS Parameter for WCDMA• Optimization Tips for WCDMA• WCDMA Tools for Drive Test• 3G Voice Call Testing• 3G Packet call & Video call testing• 3G Drive test KPI overview• 3G Optimization overview
WCDMA Introduction and Overview
• WCDMA concept and Architecture• Spreading and Scrambling• Codes and Channels• Code tree• Rake Receiver• Soft, Softer and Hard hand over• Power control - fast and slow
WCDMA – Drive test Overview using TEMS Investigation
• TEMS Parameter for WCDMA• Optimization Tips for WCDMA• WCDMA Tools for Drive Test• 3G Voice Call Testing• 3G Packet call & Video call testing• 3G Drive test KPI overview• 3G Optimization overview
Interview and drive test tips
![Page 2: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/2.jpg)
WCDMA Frequency and Spectrum
• Uplink=1920MHz -1980 MHz• Downlink= 2110MHz -2170MHz• Bandwidth=60 MHz Actual B.W assign to operator is 5MHz And out of that 3.84 MHZ is utilize.In WCDMA frequency reuse factor =1 because time and
frequency remains constant.
![Page 3: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/3.jpg)
• In WCDMA first following process is done before Reading BCCH frequency. Slot Synchronization Frame Synchronization Scrambling CodeCPICH is pilot which will read BCCH information After Synchronization .In WCDMA following Channels use for various function in UL/DL.Downlink:- Uplink:-1.DL DPCH 1.UL DPDCH2.DL CCPH 2. UL DPCCH3. P-CCPH 3. UL CPCH4. S-CCPH 4. UL PRACH5. SCH 5. HS-DPCCH6. PICH7. CPICH (primary and secondary)8. AICH
![Page 4: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/4.jpg)
WCDMA Spreading process
![Page 5: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/5.jpg)
• Spreading:- This is used to increase the B.W of the signal beyond the bandwidth normally required to accommodate information.
For Spreading OVSF code are used which is known as Orthogonal variable spreading factor code .
Spreading factor=chip rate/symbol rate .Scrambling – Scrambling is used on top of the spreading so , it
does not change the signal bandwidth but only makes the signal from different source separable from each other.
Process gain = 10 log (chip rate/bit rate)As bit rate increase process gain decrease .Cell breathing is situation where cell foot print decrease due to
large amount of user access the network beyond the capacity of that particular cell.
![Page 6: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/6.jpg)
• Eb /NO= Bit energy/Noise energy• Ec/No = Chip Energy /Noise Energy.
• Ec/No= Eb/No - process gain• As per Eb/No is fixed for each service for Ex: voice =2 and
video=4• Ec/N0= 2- 10= -8 for voice(for voice -8 is good limit)• Ec/N0= 4-18= -14 for video(for video -14 is good limit)
• Process gain(voice) = chip rate/bit rate= 10dB• Process gain (video) = chip rate /bit rate= 18dB• Chip rate = 3.84Mchips in WCDMA.
![Page 7: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/7.jpg)
WCDMA codes
![Page 8: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/8.jpg)
Code tree
![Page 9: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/9.jpg)
Rake Receiver
![Page 10: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/10.jpg)
Soft Handoff
![Page 11: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/11.jpg)
Power Control types
![Page 12: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/12.jpg)
For Speech drive Test
![Page 13: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/13.jpg)
Mobile TX power
Received signal strength indication
Target Signal to interfere ratio
Signal to interfere ratio
Speech quality mean opinion square
Dedicate channel
GSM/WCDMA
![Page 14: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/14.jpg)
Speech quality
SQI MOS Algorithm
Downlink Dedicate channel BLER%
![Page 15: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/15.jpg)
Active Set- Currently serving Cell Measured neighbor- Defined Neighbor
Detected Neighbor- Undefined strong detected serverUARFCN DL- UMTS Absolute radio frequency channel number
![Page 16: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/16.jpg)
Ranges for Radio Parameter
• 1. CPICH EC/No- 0 to -34 dB.• 2. CPICH RSCP - -15 dBm to -140 dBm for each rake finger.• 3.Ms TX power – -44 dBm to 60 dBm• 4. UTRA Carrier RSSI - -20 dBm to -140 dBm for each rake finger.• 5. SQI MOS - 1 to 5• 6. SQI - -20dBQ to 30 dBQ• 7 . SIR - -30 t0 20 db (signal interfere ratio measured on DPCCH )• 12.2 Kbit/s: 30 dBQ
10.2 Kbit/s: 28 dBQ7.95 kbit/s: 28 dBQ7.40 kbit/s: 27 dBQ6.70 kbit/s: 27 dBQ5.90 kbit/s: 24 dBQ5.15 kbit/s: 21 dBQ4.75 kbit/s: 19 dBQ
![Page 17: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/17.jpg)
Drive Test KPI
• Parameter-• RSSI – In Between -75 to -85 dbm• RSCP – In Between -75 to -85 dbm• Ec /Io – In Between -8 to -10 db• FER – 1% or 2%• Ms TX Power - Between -5 to -10• Soft Handoff – 35% of total time
![Page 18: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/18.jpg)
Use full Plots
• Server Plot – Useful to find out Swap or Overshooting.
• UE Plot - To Check Neighbour Relation.• RSCP Plot- Coverage holes• Ec /No- for good Throughput and removing
pilot pollution.• 4th best Server – Echno should be > -10db• 5th best Server – Echno should be > -10db
![Page 19: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/19.jpg)
Condition for Radio Environment
• Pilot Pollution – RSCP >= -85dBm & Ec /Io =< -10 dB Coverage Limited – RSCP <= -85dBm & Ec /Io => -10 dB Poor Radio Condition- RSCP <= -85dBm & Ec /Io =< -10 dB Good Coverage –RSCP >= -85dBm & Ec /Io => -10 dB
![Page 20: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/20.jpg)
3G –voice call testing
SCFT-Single Cell Functional Test• Before the single site verification, we should only ensure the following
conditions have been met. – Alarm Check– Cell Status Check– Parameter Check
• Alarm Check / Cell Status Check
– The product support engineer will be responsible for checking and resolving all the
alarms. It is important for the optimization engineer prior to any field test to check
with product support engineer regarding any alarms especially intermittent
alarms.
• Parameter Check
– The optimization engineer need to ensure the radio part parameters configuration
list has been achieved. In the list the radio part parameters includes: the
scrambling code, power setting, neighbor cell list, handover parameter etc.
![Page 21: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/21.jpg)
3G –voice call testing
• Site Verification Items:– Installations: CPICH RSCP, CPICH Ec/Io, Rx Antenna Swap
Test– Settings: Frequency & SC, Cell reselection parameters,
LAC/RAC, Neighbor List.– Functions: LA/RA update, 3G<->2G Cell reselection, SMS
(MT & MO), Voice (MT & MO), VP (MT & MO), PS Attach & Detach, PS service, Voice/VP/PS soft handover, Voice 3G->2G handover
![Page 22: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/22.jpg)
Testing On CELL site
– Items: Voice Call (MT & MO)
– Purpose: Verify the voice call function is normal and the voice call quality is
good
– Method: Make the dialing test of 3G voice service between two 3G mobiles,
one for the terminating call and another one for the originating call. Test the
voice communication quality
– Items: Voice Call (MT & MO)
– Purpose: Verify the voice call function is normal and the voice call quality is
good
– Method: Make the dialing test of 3G voice service between two 3G mobiles,
one for the terminating call and another one for the originating call. Test the
voice communication quality
![Page 23: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/23.jpg)
Feeder Connection Check
Test Process Items: Antenna swapping testPurpose: Verify the Rx feeder installation is right.Method: Switch the transmitter from one feeder to another, check the RSCP changed or not. If no change happened, it means that the feeder is correct.Notes: Check the RSCP from scanner
![Page 24: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/24.jpg)
Problem and Solution
• In the site verification, following problems have been found
– Scrambling Code Setting is wrong: The scrambling code from scanner and
mobile is different from the planning
– After feeder swapped, the CPICH RSCP is 20dB lower than before.• Scrambling Code Setting is wrong
– The Scrambling Code may be wrong in RNC, check the datasheet in RNC.
– If the Scrambling Code from scanner is the same as that of another sector in same site planned, maybe the TX/RX feeder is crossed to the another sector.
• After feeder swapped, the CPICH RSCP is 20dB lower than before: – The RX feeder is crossed to the antenna of another sector. In this
case, the CPICH RSCP will be high in the coverage area of the other antenna. Check the connection between the feeder and the antenna.
![Page 25: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/25.jpg)
DATA drive window
![Page 26: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/26.jpg)
Drive Test tool for drive
• Sony Ericsson C702 (capable of Scanning)• Sony Ericsson Z750i (capable of Scanning)• PCTel SeeGull LX WCDMA 2100• PCTel SeeGull LX Plus WCDMA 2100• Global Sat BU-353 (NMEA-0183)
• Garmin 10 Mobile Bluetooth (NMEA-0183)
![Page 27: 3g Drive Test Learning](https://reader033.vdocument.in/reader033/viewer/2022061114/54579fdcb1af9ff0608b494b/html5/thumbnails/27.jpg)
Thanks……