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 slowWCDMA – Drive test Overview usingTEMS 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 overviewInterview and drive test tipsWCDMA Frequency and Spectrum• Uplink=1920MHz -1980 MHz• Downlink= 2110MHz -2170MHz• Bandwidth=60 MHzActual B.W assign to operator is 5MHzAnd out of that 3.84 MHZ is utilize.In WCDMA frequency reuse factor =1 because time and frequencyremains constant.• In WCDMA first following process is done before Reading BCCH frequency.

Slot SynchronizationFrame SynchronizationScrambling 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. AICHWCDMA Spreading process

• Spreading:- This is used to increase the B.W of the signalbeyond the bandwidth normally required to accommodateinformation.For Spreading OVSF code are used which is known asOrthogonal variable spreading factor code .

Spreading factor=chip rate/symbol rate .Scrambling – Scrambling is used on top of the spreading so , itdoes not change the signal bandwidth but only makes thesignal 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 tolarge amount of user access the network beyond the capacityof that particular cell.

• 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 andvideo=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.WCDMA codesCode treeRake ReceiverSoft HandoffPower Control typesFor Speech drive TestMobile TX powerReceived signal strengthindicationTarget Signal to interfereratioSignal to interfere ratioSpeech quality meanopinion squareDedicate channel

GSM/WCDMASpeech qualitySQI MOS AlgorithmDownlink Dedicatechannel BLER%Active Set- Currently serving CellMeasured neighbor- Defined NeighborDetected Neighbor- Undefined strong detected serverUARFCN DL- UMTS Absolute radio frequency channel number

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 dBQ10.2 Kbit/s: 28 dBQ7.95 kbit/s: 28 dBQ7.40 kbit/s: 27 dBQ6.70 kbit/s: 27 dBQ5.90 kbit/s: 24 dBQ

5.15 kbit/s: 21 dBQ4.75 kbit/s: 19 dBQDrive 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 timeUse 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 removingpilot pollution.• 4th best Server – Echno should be > -10db• 5th best Server – Echno should be > -10dbCondition for Radio Environment

• Pilot Pollution –RSCP >= -85dBm & Ec /Io =< -10 dBCoverage Limited –

RSCP <= -85dBm & Ec /Io => -10 dBPoor Radio Condition-RSCP <= -85dBm & Ec /Io =< -10 dBGood Coverage –RSCP >= -85dBm & Ec /Io => -10 dB3G –voice call testingSCFT-Single Cell Functional Test• Before the single site verification, we should only ensure the followingconditions 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 resolvingall the alarms. It is important for the optimization engineer prior to any field

test to check with product support engineer regarding any alarms especiallyintermittent alarms.• Parameter Check– The optimization engineer need to ensure the radio part parametersconfiguration list has been achieved. In the list the radio part parametersincludes: the scrambling code, power setting, neighbor cell list, handoverparameter etc.3G –voice call testing• Site Verification Items:– Installations: CPICH RSCP, CPICH Ec/Io, Rx Antenna SwapTest– 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 handoverTesting On CELL site– Items: Voice Call (MT & MO)– Purpose: Verify the voice call function is normal and the voice call quality isgood– 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 thevoice communication quality– Items: Voice Call (MT & MO)– Purpose: Verify the voice call function is normal and the voice call quality isgood– 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 thevoice communication quality

Feeder Connection CheckTest ProcessItems: Antenna swapping testPurpose: Verify the Rx feeder installation is right.Method: Switch the transmitter from one feeder to another, checkthe RSCP changed or not. If no change happened, it means that the

feeder is correct.Notes: Check the RSCP from scannerProblem and Solution• In the site verification, following problems have been found– Scrambling Code Setting is wrong: The scrambling code from scannerand 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 thedatasheet in RNC.– If the Scrambling Code from scanner is the same as that ofanother sector in same site planned, maybe the TX/RX feeder iscrossed 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. Inthis case, the CPICH RSCP will be high in the coverage area of

the other antenna. Check the connection between the feederand the antenna.DATA drivewindowDrive 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)Thanks……