Huawei wcdma rno parameters optimization

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Transcript of Huawei wcdma rno parameters optimization

  • 1. Parameter Optimization

2. Review Parameteroptimization is an important stepafter RF Optimization. Parameteroptimizationimprovesservicequality and utilization of network resources. 3. Review 4. Objectives Upon completion of this course, you can:Understand the process of parameter optimizationMaster the contents of parameter optimization 5. ContentsParameter optimization procedure Parameter optimization contents 6. Parameter Optimization Process 7. Data Input and Find ProblemsFind problems from the input data, such as: Low success rate of call setup Low success rate of handover High rate of call drop 8. Verify Parameter Problems 9. Parameter Classification MobileManagement Parameters PowerControl Parameters PowerConfiguration Parameters Load OtherControl Parameters Parameters 10. Determine Parameter Values Listthe form for changing parameters(original parameter values vs. new parameter values) ListMML commands for changing parametersNote: Maybe some tradeoff considerations need to be considered to assure the maximal improvement in the whole view such as coverage and capacity, fast and stable, improvement and risk, cost (or efforts) and gain. 11. Impact Impacton customer service and other networks Impacton OMC (efforts, maintenance) 12. Prepare Test Plan and Change Parameters Preparetest schedule, routes, tools and be ready to getInformation. Changeparameters and make records. 13. Course ContentsParameter optimization Procedure Parameter optimization Contents 14. Parameter Optimization Contents MobileManagement parameter optimization PowerControl parameter optimization PowerConfiguration parameter optimization LoadControl parameter optimizationNote: There are too many parameters to introduce. Only some parameters about network optimization are mentioned here and maybe more parameters need to be added in the future. 15. Mobile Management Parameter OptimizationCell Selection & ReselectionThe changing of cell on which UE camped in idle mode or in Cell FACH, Cell PCH, URA PCH states. That assures UE camping the most suitable cell, receiving system information and establishing an RRC connection on a best serving cell. HandoverThe changing of cells with which UE connected in DCH mode. That assures seamless coverage and load balancing. 16. Cell Selection & Reselection Procedure go here whenever a new PLMN is selectedcell information stored for the PLMN Stored information Cell Selection no suitable cell foundno cell information stored for the PLMN1Initial Cell Selectionno suitable cell found2suitable cell foundsuitable cell found no suitable cell foundCell Selection when leaving connected modereturn to idle modesuitable cell foundleave idle modeConnected modeCamped normallyNAS indicates that registration on selected PLMN is rejected (except with cause #14 or #15 [5][16])trigger suitable cell foundCell Reselection Evaluation Processno suitable cell foundAny Cell Selectionno acceptable cell foundgo here when no USIM in the UEUSIM inserted acceptable cell found Cell Selection when leaving connected modereturn to idle modeConnected mode (Emergency calls only)acceptable cell foundleave idle modeCamped on any cellsuitable cell found12trigger acceptable cell foundCell Reselection Evaluation Processno acceptable cell found 17. Cell Selection Criteria (S Criteria)The cell selection criterion S is fulfilled when: for FDD cells:Srxlev > 0 AND Squal > 0for TDD cells:Srxlev > 0Where: Squal = Qqualmeas Qqualmin Srxlev = Qrxlevmeas - Qrxlevmin - PcompensationWhen a UE wants to select a UMTS cell, the cell must satisfy S criterion. 18. Cell Selection Parameters 19. Cell Re-selection Measure Condition Use Squal for FDD cells and Srxlev for TDD for Sx1. If Sx > Sintrasearch, UE need not perform intra-frequency measurements. If Sx Sintersearch, UE need not perform inter-frequency measurements. If Sx SsearchRAT m, UE need not perform measurements on cells of RAT m". If Sx Tother_RAT + H/2 Tother_RAT : the inter-system handover decision threshold; Mother_RAT : the inter-system (GSM RSSI) measurement result received by RNC; CIO: Cell Individual Offset, which is the inter-system cell setting offset; H : refers to hysteresis, If the formula is met, a trigger-timer called TimeToTrigForSysHo will be started, and a handover decision will be made when the timer times out; Note: if the inter-system quality satisfies the following condition before the timer times out: Mother_RAT + CIO < Tother_RAT - H/2 The timer will be stopped, and RNC will go on waiting to receive the next inter-system measurement report. The length of the trigger-timer is called time-to-trigger. 36. Inter-system Handover Parameters 37. Parameter Optimization Contents MobileManagement parameter optimization PowerControl parameter optimization PowerConfiguration parameter optimization LoadControl parameter optimization 38. Power Control parameter optimizationPowerControl Characteristics Minimize the interference in the network, thus improvecapacity and quality Maintain the link quality in uplink and downlink by adjusting the powersMitigate the near far effect by providing minimum required power level for each connectionProvides protection against shadowing and fast fading 39. Power Control Classification Open Loop Power Control Open loop power control is used to determine UEs initial uplink transmit power in PRACH and NodeBs initial downlink transmit power in DPDCH. It is used to set initial power reference values for power control. Outer Loop power control Outer loop power control is used to maintain the quality of communication at the level of bearer service quality requirement, while using as low power as possible. Inner loop power control (also called fast closed loop power control) Inner loop power control is used to adjust UEs uplink / NodeBs downlink Dpch Power every one slot in accordance with TPC commands. Inner loop power control frequency is 1500Hz. 40. Open Loop Power Control - UplinkBCH PICH channel power BCH C PICH channel power C UL interference leve UL interference leve Constant Value Constant ValueRACH RACHMeasure CPICH_RSCP Measure CPICH_RSCP and determine the initial and determine the initial transmitted power transmitted powerPreamble_Initial_Power = Primary CPICH TX power - CPICH_RSCP + UL interference + Constant Valuewhere Primary CPICH TX power, UL interference and Constant Value are broadcasted in the System Information and CPICH_RSCP is the measured value by UE 41. Open Loop Power Control - Downlink Determine the downlink initial power Determine the downlink initial power control control DCH DCHRACH reports the RACH reports the measured value measured valueMeasure CPICH Ec/I0 Measure CPICH Ec/I0P=Eb R E ( PCPICH /( c )cpich Ptotal ) Io W Io Where R is the user bit rate. W is the chip rate (3.84M). Pcpich is the Primary CPICH transmit power. Eb/Io is the downlink required Eb/Io value for a bearer service. (Ec/Io)cpich is measurement value reported by the UE. is downlink cell orthogonal factor. Ptotal is the current cells carrier transmit power measured at the NodeB and reported to the RNC. 42. Open Loop Power Control Parameters 43. Outer Loop Power Control M acr o di ver si t y M acr o di ver si t y com ni ng bi com ni ng bi S N R C Set SI R tt ar get et S R ar get I SSet SI R tt ar get et S R ar get I SD N R C Set SI R et S R I S tt ar get ar getOuter loop control is used to setting SirTarget (Signal to Interference Ratio Target) for inner loop power control. It is divided into uplink outer loop power control and downlink outer loop power control. The uplink outer loop power control is controlled by SRNC (serving RNC) for setting a target SIR for each UE. This target SIR is updated according to the estimated uplink quality (Block Error Ratio/ Bit Error Ratio). If UE is not in DTX (Discontinuous Transmission)status (that means RNC can receive uplink traffic data), RNC will use Bler (Block Error Ratio) to compute SirTarget . Otherwise, RNC will use Ber (Bit Error Ratio) to compute SirTarget. The downlink outer loop power control is controlled by the UE receiver to converge to required link quality (BLER) set by the network (RNC) in downlink. 44. Outer Loop Power Control Parameters 45. Inner Loop Power Control The inner loop power control adjusts the UE or NodeB transmit power in order to keep the received signal-to-interference ratio (SIR) at a given SIR target, SIRtarget.It is also divided into uplink inner loop power control and downlink inner loop power control. 46. Uplink Inner Loop Power Control UTRAN behaviour The serving cells (cells in the active set) should estimate signal-to-interference ratio SIRest of the received uplink DPCH. The serving cells should then generate TPC commands and transmit the commands once per slot according to the following rule: if SIRest > SIRtarget then the TPC command to transmit is "0", while if SIRest < SIRtarget then the TPC command to transmit is "1".UE behaviourUpon reception of one or more TPC commands in a slot, the UE shall derive a single TPC command, TPC_cmd, for each slot, combining multiple TPC commands if more than one is received in a slot. This is also valid when SSDT transmission is used in the downlink. Two algorithms shall be supported by the UE for deriving a TPC_cmd. Which of these two algorithms is used is determined by a UE-specific higher-layer parameter, "PowerControlAlgorithm",andisunderthecontroloftheUTRAN.If"PowerControlAlgorithm" indicates "algorithm1", then the layer 1 parameter PCA shall take the value 1 and if "PowerControlAlgorithm" indicates "algorithm2" then PCA shall take the value 2. 47. Uplink Inner Loop Power ControlThe step size DTPC is a layer 1 parameter which is derived from the UE-specific higherlayer parameter "TPC-StepSize" which is under the control of the UTRAN. If "TPCStepSize" has the value "dB1", then the layer 1 parameter DTPC shall take the value 1 dB and if "TPC-StepSize" has the value "dB2", then DTPC shall take the value 2 dB. The parameter "TPC-StepSize" only applies to Algorithm 1 . For Algorithm 2 DTPC shall always take the value 1 dB.After deriving of the combined TPC command TPC_cmd using one of the two supported algorithms, the UE shall adjust the transmit power of the uplink DPCCH with a step of DDPCCH (in dB) which is given by:DDPCCH = DTPC TPC_cmd. 48. Uplink Inner Loop Power Control Algorithm 1 for processing TPC commands When a UE is not in soft handover, only one TPC command will be received in each slot. In this case, the value of TPC_cmd shall be derived as follows: - If the received TPC command is equal to 0 then TPC_cmd for that slot is 1. - If the received TPC command is equal to 1, then TPC_cmd for that slot isAlgorithm 2 for processing TPC commands When a UE is not in soft handover, only one TPC command will be received in each slot. In this case, the UE shall process received TPC commands on a 5-slot cycle, where the sets of 5 slots shall be aligned to the frame boundaries and there shall be no overlap between each set of 5 slots. The value of TPC_cmd shall be derived as follows: - For the first 4 slots of a set, TPC_cmd = 0. -For the fifth slot of a set, the UE uses hard decisions on each of the 5 received TPC commands as follows: If all 5 hard decisions within a set are 1 then TPC_cmd = 1 in the 5th slot. If all 5 hard decisions within a set are 0 then TPC_cmd = -1 in the 5th slot. Otherwise, TPC_cmd = 0 in the 5th slot. 49. Downlink Inner Loop Power Control UEbehaviourThe UE shall generate TPC commands to control the network transmit power and send them in the TPC field of the uplink DPCCH. The UE shall checkthe downlink power control mode (DPC_MODE) before generating the TPC command: If DPC_MODE = 0 : the UE sends a unique TPC command in each slot and the TPC command generated is transmitted in the first available TPC field in the uplink DPCCH;If DPC_MODE = 1 : the UE repeats the same TPC command over 3 slots and the new TPC command is transmitted such that there is a new command at the beginning of the frame.The DPC_MODE parameter is a UE specific parameter controlled by the UTRAN. 50. Downlink Inner Loop Power Control UTRANbehaviourUpon receiving the TPC commands UTRAN shall adjust its downlink DPCCH/DPDCH power accordingly. For DPC_MODE = 0, UTRAN shall estimate the transmitted TPC command TPCest to be 0 or 1, and shall update the power every slot. If DPC_MODE = 1, UTRAN shall estimate the transmitted TPC command TPCest over three slots to be 0 or 1, and shall update the power every three slots. 51. Inner Loop Power Control Parameters 52. Parameter Optimization Contents MobileManagement parameter optimization PowerControl parameter optimization PowerConfiguration parameter optimization LoadControl parameter optimization 53. Physical Channels Types 54. Common Channel ParametersAll channels power refers to PCPICH power expect PCPICH. 55. Dedicated Channel ParametersDedicated Channel Power refers to PCPICH Power. 56. Parameter Optimization Contents MobileManagement parameter optimization PowerControl parameter optimization PowerConfiguration parameter optimization LoadControl parameter optimization 57. Load Control Parameter OptimizationCallAdmission Control (CAC)Call admission control is used to control cells load by admission/rejection request to assure a cells load under control.Dynamic Channel Configuration Control (DCCC) Dynamic Channel Configuration Control is used to dynamically change a connections load to improve cell resource utilization and control cells load. 58. Call Admission Control Procedure 59. Call Admission Control ParametersDifferent service type can be configured different threshold. That means leave some resources for important service ( or request), such as HO > Conversation > Other. Ul(Dl)TotolKThd is used when NodeB load report is not available . It uses equivalent 12.2k-voice users number method. 60. Dynamic Channel Configuration Control Dynamic channel configuration control (DCCC) aims to make full use of radio resource (codes, power, CE )Rate or band- Configured bandwidth is fixed with no DCCC - Configured bandwidth is changing with DCCC - Traffic rate 61. DCCC Procedure Traffic Volume measurement controlUE and RNC MeasurementMeasurement reportDCCC decisionDCCC execution 62. Traffic Volume Measurement Transport Channel Traffic Volume ThresholdTimeReporting event 4AReporting event 4ATransport Channel Traffic VolumeThreshold TimeReporting event 4BReporting event 4BReporting event 4B 63. DCCC Decision 1) 4a event report -> increase bandwidth 4b event report -> decrease bandwidth 2) if current bandwidth