UMTS Optimization

UMTS Optimization 1-IntroductionThe following concepts should be fully introduced 1-WCDMA system survey.WCDMA basic concepts.Spreading; processing gain; Ec/No and Eb/NoCapacity limitation Power; Codes and interference. Channelization coding channel switching and scrambling coding primary and secondary .WCDMA architecture.UE domain; UTRAN domain and Core network domain.Functionality of Node B and RNC.WCDMA Air Interface concept.Chip rate; BW; modulation and frame structure.Different RABs available 12.2, 64, 128, 144, 384kb/sec.Radio channels P-CCPCH; SCH; S-CCPCH; P-CPICH; DPDCH; DPCCH; AICH; PICH and PRACH.WCDMA air interface modes Idle; Cell_DCH; Cell_FACH; Cell_PCH; URA_PCH

01-Feb-1431-WCDMA system survey.WCDMA Air Interface procedure.Synchronization.RACH and Call setup.Handover Soft and Hard.Power Control.

01-Feb-144The following concepts should be fully introduced 2- WCDMA Planning.WCDMA Basic planning concept.Capacity basic principle .Coverage basic principle link budget equation parameters.Coverage and Capacity planning inter-dependency.Load concept.Node B configuration and parameters PA; channel elements and antenna design.Soft Handover planning.

01-Feb-145The following concepts should be fully introduced

Capacity & Coverage DimensioningThe final site annual plan, resulted from combining coverage, capacity and quality dimensioning, taking into accounts the practical limitationVisiting the nominated location to assess the real environment to determine whether it is a suitable site location

Interacting with the rollout team to choose a suitable location, and finalize the site design (height, orientation, tiltetc) and determine the needed equipment.

installing the site according to its RF design

Introduction to OptimizationInteracting between planning performance and optimization teams to tune the parameters of the site to achieve its optimum performance

Annual exercise in order to determine the number of extra sites to be deployed and its initial place

Optimization is the final stage of the network design..the final stage include tuningActions needed to adjust network performance to reach the target KPIs 6Optimization flow.01-Feb-147System Counters& StatisticsSystem Parameters & featuresOptimization Scope.01-Feb-148User Ability to obtain service within specific tolerance call and paging setup success rate blocking rateUser Ability to continue obtaining service for the requested duration drop call rateUser ability to obtain service with the needed qualityPS and SC has different definition for each indicatorsCounters and ParametersCounters.RNC and NodeB Counters are implemented to record events for each action take place on the air interface.Counters can be defined for daily and peak hour counters.Counters should be fetched through data base tools to obtain systems statistics. Business object.Parameters.RNC and NodeB are configured through logical parameters.Each feature is defined through set of parameters.Parameters can be defined as default and optional.Parameters can be viewed or modified through OSS tools.01-Feb-149CountersType of CountersPeg Counter: a counter that increased by 1 at each occurrence of a specific activity. Gauge Counter: a counter that can be increased or decreased depending on the activity of the system.Accumulator counter: a counter that can be increased by a value of sampleScan Counter: a counter that is increased by 1 each time its corresponding accumulator counter increasesPDF counter: a counter that has a certain ranges of values.

01-Feb-1410Counters classifcations.RBS counter.RNC counter.Transport network counter.

CountersCounters characteristicCounters can be defined.DailyHourlyBusy Hour.Busy hour 3G counter is defined on the load behavior not the traffic behavior.Recording data STS should be done during the total period of sampling; thus cell operational have to be checked; before STS are evaluated.pmCellDownTimeMan:pmCellDownTimeAuto:

01-Feb-1411Problems solvingProblems related to the radio network.Dimensioning, planning and Architecture.Hardware problems.Uplink or Downlink interference.Handover and IRAT handover.Pilot Pollution.Idle Mode parameters.Code allocation.Admission control.Connection Control.Power Control.Other cell parameters.

01-Feb-14122-Accessibality analysis

01-Feb-1413AccessibilityAccessibility is defined as the ability of the user to obtain the requested service from the system.Idle Mode.Random Access.RRC connection.NAS non access stratum.RAB assignment.

01-Feb-1414What is Idle Mode? UE in IDLE MODE has the following properties :UE is Powered ON , while it doesn't have connection to the Radio Network

UE is synchronized with Radio Network and can read broadcast information , Accordingly UE can access the Network request services .

UE is registered on the network , updating Network with its LAC , Accordingly UE becomes reachable by the network

01-Feb-1415Services Types in Idle Mode Normal ServiceWhen the UE select accepted level cell in its HPLMN Limited ServiceWhen the UE didnt find any accepted level cells at its home PLMN it selects any accepted level cell at any other PLMNOperator reserved servicesThe operator can reserve any cell for testing only and this through two parameters cell reserved and Access classNbarred 01-Feb-1416The operator can establish cell access restrictions using the cellReservedparameter that allows the reservation of a cell for operator use only. It is alsopossible to restrict access for certain Access Classes using the parameteraccessClassNbarred. Both parameters are sent in the system information.Idle Mode Behavior PLMN selection Cell Selection / Reselection Paging Location Update and Routing area update System Information 01-Feb-141701-Feb-1418Cell SearchUE SynchronizationInitiate Cell SynchronizationP-CCPCH(PSC + SSC + BCH)

UE Monitors Primary SCH code, detects peak in matched filter outputSlot Synchronization Determined ------>UE Monitors Secondary SCH code, detects SCG and frame start time offsetFrame Synchronization and Code Group Determined ------>UE Determines Scrambling Code by correlating all possible codes in groupScrambling Code Determined ------>UE Monitors and decodes BCH dataCell Synchronization CompleteTCell parameter is used to insure proper synchronization in the same nodeBPLMN Selection PLMN Selection 01-Feb-1419Whenever a UE is switched on or enters an area with acceptable coverage after coverage loss, it attempts to camp on the last registered PLMN or equivalent PLMNTo speed up the PLMN selection procedure, the UE uses information about the last registered PLMNcarrier frequencieslist of neighboring cells stored.Mobile identify PLMN through PLMN identity, which consists of mcc and mnc. If the registration attempts fails mobile is searching for a new PLMN according to one of the following algorithmsAutomatic mode Manual mode.Automatic PLMN selection Automatic ModeHome PLMN (HPLMN), if not previously selected, according to the RadioAccess Technologies (RATs) supported by the UE.Each PLMN in the user-controlled PLMNs list in the USIM, if present, in order of priority, according to the RATs supported by the UE Each PLMN in the operator-controlled PLMNs list in the USIM, in order of priority, according to the RATs supported by the UE Other PLMNs, according to the high-quality criterion (-95 dBm RCSP ), in random order Other PLMNs that do not fulfill high-quality criterion, in order of decreasing signal strength (SS)01-Feb-1420Automatic PLMN selection 01-Feb-1421

Manual PLMN Selection UE displays all the available PLMNS after carriers scanning All the available PLMNs will appear regardless it is allowed or not and ignoring the forbidden LACs

01-Feb-1422f2 fn

PLMN APLMN BHPLMNPLMN E

f1

Strongest cell0.20.40.60.811.21.41.61.8x 107-40-20020406080FrequencyPower Spectrum Magnitude (dB)

Roaming It is the services in which the user will be able to obtain services from another PLMN Same country (national roaming)Another country (international roaming) Every 30 minutes the UE try to reselect its home PLMN 01-Feb-1423Cell selection and reselection procedure The cell selection and reselection process allows the UE to look for a suitablecell in the selected PLMN and to camp on it. When a suitable cell is found, the UE camps on it in a state defined as camped normally. In this state, the UE monitors paging and system information, performs periodical radio measurements, and evaluates cell reselection criteria. If the UE finds a better cell, that cell is selected by the cell reselection process. The change of cell may imply a change of the RAT.01-Feb-1424Cell selection and reselection procedure 01-Feb-1425

Cell selection occurs whenWhen UE is switched on When UE in idle mode has had a number of failed RRC connection request When a UE returns to idle mode from the connection mode on common channel (cell-FACH) after a number of failed cell update UE returns to idle mode from connected mode (cell-DCH)When a UE returns to idle mode after an emergency call on any PLMN 01-Feb-1426Cell selection criteria.Squal = Qqualmeas qQualMin > 0 Qqualmeas is CPICH Ec/NoqQualMin is minimum required Ec/NoSrxlev = Qrxlevmeas - qRxlevMin Pcompensation Qrxlevmeas is CPICH RSCPqRxlevMin is minimum required RSCPPcompensation = max (maxTxPowerUl - P, 0);01-Feb-1427The cell selection is performed based on the below criteriaThe criteria is chosen based on qualMeasQuantity qualMeasQuantity = 2 is CPICH Ec/No.qualMeasQuantity = 1 is CPICH RSCP.

Squal and Srxlev should be valid to select cell, qualMeasQuantity is used to determine the reselection will based on EcNo or RSCP27Cell reselection procedure When it occurs? When cell on which it is camping is no longer suitable (S criteria)When there is any neighbor with better quality than the selected one (R criteria) When the UE in the limited service state on an acceptable cell When the UE is in cell _FACH state 01-Feb-1428Idle Mode behavior?After performing cell selection; the mobile reads the broadcasting information on the PCCPCH; the enter a sleeping mode; wake up every DRX-cycle to for the following activities.Read PICH.Evaluate S criteria.Evaluate R criteria.DRX cycle should be optimized to balance the battery consumption (too low), and to achieve good mobility performance (too high)DRX cycle = 2^(K) * 10ms. K cnDrxCycleLengthCs or cnDrxCycleLengthPs

DRX-CycleDRX-CycleDRX-CyclecnDrxCycleLengthCs cnDrxCycleLengthPs640ms-1.28 secNormally cnDrxCycleLengthCs equals cnDrxCycleLengthPs equals 628Cell reselection triggers01-Feb-1429SintraSearch : Controls when intra-frequency measurements are performed1. Intra frequency measurements starts when Squal