1 IntroductionUMTS RAN Network High Level Designfor DIGITEL RNC RPR

Network Expansion Methodology and Expansion Solution

Counters in this document are not allowed to show to the customer without permission.Network Evaluation Methodology and Expansion Solution Proposal(RAN12.0)

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Revision RecordDateVersionCR IDRevision DescriptionAuthor

2009-04-30Initial Version Template for the network evaluation and expansion proposalLi Hong(51769)

2009-06-122.0Give other options for some items like CE,Iub,etc when the counters are not accurate.Patch version are also detailed.Li Hong(51769)

2009-07-122.1According to the problems of the counters, methodology updated accordingly.Li Hong(51769)

2009-12-223.0Expansion evaluation methodology is updated and completed. Expansion solution is detailed. Give wording for the whole document.Li Hong(51769)

2010-08-184.0Full document wording. Update the evaluation and expansion for the HS-PDSCH codes license resources. Update the HSDPA user experiences evaluation. Update the RNC license evaluation part.

Li Hong(51769)

2011-03-244.1BHCA utility ratio is closely related to SPU CPU usage and the evalution process is quite complicated, so delete the BHCA utility partUpdate to fit RAN12.0 versionLi Hong(51769)

Change Request (CR) RecordCR IDCR OriginatorCR DateCR DescriptionCR Feedback

Issue 1.0 (2008-08-20)Commercial in ConfidencePage 1 of 29

Contents1 Introduction81.1 Network Evaluation Objectives81.2 Scopes of this document82 Network Evaluation Methodology102.1 Network Evaluation Procedures112.2 Evaluation Period122.3 Optimization Check before Give Expansion Suggestion122.4 Coverage evaluation132.5 RF Resource Evaluation142.5.1 CE Utilization Status Evaluation142.5.2 Codes Utilization Ratio Evaluation152.5.3 Downlink Loading Evaluation172.5.4 Uplink RTWP Status Analysis182.6 HSDPA Subscriber Perception Evaluation182.7 Iub Transmission Evaluation192.8 HSDPA Codes Evaluation202.8.1 HS-PDSCH Codes License Evaluation202.8.2 HS-SCCH Codes Utilization Evaluaton202.9 RNC License Evaluation202.10 RNC HW Evaluation212.10.1 SPU212.10.2 DPU222.11 Why 70% mean threshold is suggested?232.12 Evaluation Threshold Margin263 Target Network Planning273.1 General Target Network Planning Strategy273.2 Expansion suggestion for Licenses limited scenario273.3 Expanion suggestion for RF resources limited scenario283.4 Target Network Traffic Requirement293.5 Target Network Configuation293.5.1 Final NodeB Configuation293.5.2 Final CE Configuation303.5.3 Iub Transmission Configuration31FiguresFigure 21 Network expansion evaluation procedure12Figure 21 TP combined with EcIo to show the coverage situation14

TablesTable 31 Traffic increase and network expansion for operators target network29Table 32 List of New Cells introduced30Table 33 List of New Sites introduced30Table 34 Final CE configuration30Table 35 Final Iub configuration31

AbbreviationsAbbreviationsDetailed Description

TPTransport Propagation Delay, which defined in 3GPP

RTWPReceived Total Wideband Power

TCPTotal Carrier Power

CEChannel Element

HSDPAHigh speed downlink packet access

HSUPAHigh speed uplink packet access

CCHCommon Channel

OVSFOrthogonal Variable Spreading Factor

IntroductionNetwork Evaluation ObjectivesThis document is for RAN10.0 and RAN11.0 version.Network evaluation is very important to keep network competitive and healthy. Huawei professional network evaluation provides the real time network performance and resources utilization evaluation to give operators a full and on going figure of the network.Network Evaluation mainly includes following aspects: Network radio resources utility ratio analysis Network hardware resources utility ratio analysis Network transmission utility ratio analysis Network major performance analysis Network subscriber perception (HSPA) analysisA deep, complete and professional network evaluation will benefit operator in the following aspects: Shows the potential problems and risks Shows the current network bottlenecks Overall understanding of network performance and potential limit Basis of professional network expansion suggestionScopes of this documentThis document provides detailed coverage, capacity and resources evaluation guidelines. Section 2 gives the detailed introduction of the network evaluation. Evaluation procedures and methodology are detailed in this part.Section 3 gives the general description of the target network planning in term of expansion.

Network Evaluation MethodologyKPIHSPACETCPRTWP123CPUDetailed network evaluation principles and procedures are depicted in this section.The utilization ratio of RF resources including OVSF codes, CE, Power (TCP) and RTWP will be analyzed, and rejection due to resource congestion will be evaluated as well.HSPA user perception will be analyzed and used as the important reference for the situation which total Power (TCP) or codes exceed the specified threshold.Also, RNC hardware and transmission status at Iub interface will be analyzed.These evaluation results are to be used for the network expansion suggestion.

Network Evaluation Procedures

Performance Data SamplingNetwork EvaluationNetwork Evaluation ReportRF resources occupied by R99 exceed threshold?Transmission /Hardware Resources Utilization exceed threshold?NoHSPA User Experiences is good or not?NoYesYesNeed Transmission /Hardware ExpansionRF resources occupied with HSDPA exceed threshold?Potential Busy Cell or Node BGive optimization suggestion for the problem detectedYesENDPotential Busy Cell or Node BYesNoCheck parameter configurationFigure 21 Network expansion evaluation procedureAs showed in Figure 1-2, there are 3 main steps for the network expansion evaluation:Step1: Preparation and data sampling Background of the network, existing network performance data are needed as the input of the network evaluation. Huawei M2000 and NASTAR platform make the data sampling very easy and convenient.Step2: Detect the problem and give optimization suggestion From the network overall evaluation, some problems will be detected and could be solved by optimization. Detailed optimization suggestion will be proposed in this phase.Step3: Detailed analysis for expansion Few steps are taken to evaluate the network and find the resources limitation aspects, which could be used as the basis for the expansion solution. For the Potential busy cells or NodeB, expansion such as add more carrier or NodeB is suggested. Detailed evaluation principles will be depicted in following sections.Evaluation PeriodTo make a complete and accurate network evaluation and reflect the real situation of the existing network, evaluation period definition is quite important. Based on the experiences from Huawei, suggestion on evaluation period is given as following. Sample data from late N days and get the most busy hour value (BH) in each day (24 hours), so we will have N BHs. Then normally we give 3 evaluation period modes:1) Get the maximum value in all these N BHs, that is : Final BH = max( BH N1, BH N2, ... BH Nn)2) Get the average value for all these N BHs, that is: Final BH = average(BH N1, BH N2, ... BH Nn)3) Select top 3 in all these N BHs, get the average value of these top 3 as the final value, that is: Final BH = average( top 3(BH N1, BH N2, ... BH Nn)) Important notes: N days mentioned above could be continuous or not continuous, could be one week or one month, depends on the actual situation, normally continuously one week is suggested. Busy Hour (BH) value is defined as the hour which has the biggest traffic and leads to highest RF resources utilization. For instance, BH for CE utilization is the hour has the biggest CE consumption of one NodeB, so each Node B has only one CE BH in each day, the same for other RF resources.Optimization Check before Give Expansion SuggestionFor the resources especially RF resources limitation, some are caused by bad optimization or wrong parameters setting, some are caused by too much traffic or both of them. So before we come to the Need expansion conclusion, configuration and optimization parameters check are the first important things to do.If there are still congestions or high resources utilization after the optimization checking, then expansion may be needed. More investigation which detailed in the following sections is needed to identify the potential problems and give solutions.Coverage evaluationCoverage problem needs to be considered in expansion. There are two ways to evaluate the coverage situation of the existing commercial network. One is DT (Drive Test), another efficient way is Huawei TP analyzer tools. More details are given in the following for TP analyzer tools.RSCP, Ec/Io and TP values (represents distance from user to base station) are contained in PCHR data, TP analyzer will give clearly coverage status analysis with the PCHR data.Plots example shown below (Ec/Io combined with TP value distribution):

Figure 21 TP combined with EcIo to show the coverage situationWhere,1 TP means 3chips delay, which represents 234m distance. (1 chip represents 78m)TP=0, means 0m~234mTP=1, means 234m~2*234m From the plots above, we can see that TP value smaller than 2 which means UE to NodeB distance smaller than 702m occupies almost 80% areasmaller than 5 occupies more than 95% area. At the same time Ec/Io better than -12dB occupies the most of the samples. So the coverage of this network is pretty good.TP analyzer could give results based on whole network or each RNC.Also TP analyzer could analyze all the HSDPA throughput distribution, CQI, RSCP and Ec/Io history data, based on these data, the HSDPA low throughput problem caused by poor coverage will be identified.

Note:Please apply TP analyzer tool from Li Hong (ID: 51769)

RF Resources EvaluationCE Utilization Status EvaluationCE is the baseband resources for services in NodeB. CE utilization ratio represents the base band resources consumption status of the NodeB. If the CE utilization ratio exceeds one specified threshold of the total CE, that means CE resources are going to be the limitation of the network. CE expansion is needed in this case.Mean CE consumption and Max CE consumption in one NodeB at Busy Hour (BH) are used for the evaluation. Principles:The CE utilization ratio analysis principle is shown below:1The mean CE utilization ratio should not exceed 70% due to HUAWEIs experiences, if yes, expansion is recommended.2) Congestion ratio due to insufficient CE resources should be less than 0.5%.If the mean CE utilization ratio doesnt exceed 70%, but he max CE consumption (UL_Max_Used_CE_Number, DL_Max_Used_CE_Number) exceeds the CE license configuration for one NodeB, congestion due to CE problems are also happened a lot at the same time, then expansion is suggested.Formulas to get the mean CE consumption in one NodeB are:UL Mean CE Utility Ratio = UL_Mean_Used_CE_Number_in_BH / Configured_UL_CE_NumberDL Mean CE Utility Ratio = DL_Mean_Used_CE_Number_in_BH / Configured_DL_CE_NumberWhere,

If in Non-RAN sharing case,UL_Mean_Used_CE_Number_in_BH uses counter VS.LC.ULMean.LicenseGroup.SharedDL_Mean_Used_CE_Number_in_BH uses counter VS.LC.DLMean.LicenseGroup.SharedUL_Max_Used_CE_Number uses counter VS.LC.ULMax.LicenseGroup.Shared;DL_Max_Used_CE_Number uses counter:VS.LC.DLMax.LicenseGroup.Shared;Configured_UL_CE_Number could use counter: VS.LC.ULCreditAvailable.LicenseGroup.Dedicated+VS.LC.ULCreditAvailable.SharedConfigured_DL_CE_Number could use counter: VS.LC.DLCreditAvailable.LicenseGroup.Dedicated+VS.LC.DLCreditAvailable.Shared

If in RAN sharing case,UL_Mean_Used_CE_Number_in_BH= VS.LC.ULMean.LicenseGroup + VS.LC.ULMean.LicenseGroup.Shared;DL_Mean_Used_CE_Number_in_BH =VS.LC.DLMean.LicenseGroup + VS.LC.DLMean.LicenseGroup.Shared;UL_Max_Used_CE_Number = VS.LC.ULMax.LicenseGroup+VS.LC.ULMax.LicenseGroup.Shared;DL_Max_Used_CE_Number= VS.LC.DLMax.LicenseGroup+VS.LC.DLMax.LicenseGroup.Shared;Configured_UL_CE_Number could use counter: VS.LC.ULCreditAvailable.LicenseGroup.Dedicated+VS.LC.ULCreditAvailable.SharedConfigured_DL_CE_Number could use counter: VS.LC.DLCreditAvailable.LicenseGroup.Dedicated+VS.LC.DLCreditAvailable.Shared

Congestions due to insufficient CE could be sampled by the following counters:VS.RRC.Rej.ULCE.CongVS.RAB.FailEstabCS.ULCE.CongVS.RAB.FailEstabPS.ULCE.CongVS.RRC.Rej.DLCE.CongVS.RAB.FailEstabCS.DLCE.CongVS.RAB.FailEstabPS.DLCE.CongCongestion ratio due to insufficient CE resources can be calculated and evaluated by following formulas:(VS.RRC.Rej.ULCE.Cong / VS.RRC.AttConnEstab.Sum) < 0.5 %(VS.RRC.Rej.DLCE.Cong / VS.RRC.AttConnEstab.Sum) < 0.5 %(VS.RAB.FailEstabCS.ULCE.Cong / VS.RAB.AttEstabCS.Conv) < 0.5% (VS.RAB.FailEstabCS.DLCE.Cong / VS.RAB.AttEstabCS.Conv) < 0.5% (VS.RAB.FailEstabPS.ULCE.Cong / (VS.RAB.AttEstabPS.Str + VS.RAB.AttEstabPS.Int +VS.RAB.AttEstabPS.Bkg)) < 0.5 %(VS.RAB.FailEstabPS.DLCE.Cong /(VS.RAB.AttEstabPS.Str + VS.RAB.AttEstabPS.Int +VS.RAB.AttEstabPS.Bkg) )< 0.5 %

NOTECOUNTERs marked in blue above are not suggested to show to the customer.

Codes Utilization Ratio EvaluationCodes here are the OVSF codes for both R99 and HSPA services. If the codes utilization ratio exceeds one specified threshold, that means codes resources are going to be the limitation of the network. Normally mean codes consumption in one NodeB at Busy Hour (BH) is used for the evaluation. Principles for the codes utilization are:1) The mean codes utilization for R99 services should not exceed 70%.2) Congestions due to insufficient codes in busy hour of the cell should not exceed 0.5%.3) The mean codes utilization for total services should not exceed 70%If 1is not met, the codes allocation between R99 services and HSDPA services can be adjusted firstly according to the service distribution. If it is still not OK, then more carriers and sites are suggested. If 2) is not met for a period of time, the adjustment suggestion is the same to 1).If 3) is not met, then more investigation is needed for the HSDPA single user perception.Formulas to get the mean R99 codes utilization ratio in one NodeB are:R99_Code_Utility_Ratio = R99_Mean_Used_Code_in_BH / R99 Available CodesWhere, R99_Mean_Used_Code_in_BH = ( + ) * 64 + ( + ) * 32 + ( + ) * 16 + ( + ) * 8 + ( + ) * 4 + ( + ) * 2 + ( + )R99 Available Codes=256-(Codes used by R99 CCH+Codes used by HUSPA downlink CCH + Codes used by HS-SCCH of HSDPA + Minimum codes allocated to HSDPA*16 =256-(12+3+4+Minimum codes allocated to HSDPA*16) [simplified]=256-(19+Minimum codes allocated to HSDPA*16) [More simplified]

For the codes consumption by all the services including CCH+ R99 + HSDPA, counters blow can be used:VS.RAB.SFOccupy means the mean codes used with all services.VS.RAB.SFOccupy.MAX means the maximum codes used with all services.So the total OVSF codes (R99+H) utilization at BH in each cell can be evaluated by this formula:Total_OVSF_Codes_Utilization=VS.RAB.SFOccuy/256Congestions due to insufficient downlink codes can be sampled by the following counters:VS.RRC.Rej.Code.CongVS.RAB.FailEstabCS.Code.Cong VS.RAB.FailEstabPS.Code.CongCongestions due to insufficient codes in busy hour can be calculated and evaluated by following:(VS.RRC.Rej.Code.Cong / VS.RRC.AttConnEstab.Sum ) < 0.5%(VS.RAB.FailEstabCS.Code.Cong / VS.RAB.AttEstabCS.Conv) < 0.5%(VS.RAB.FailEstabPS.Code.Cong / (VS.RAB.AttEstabPS.Str + VS.RAB.AttEstabPS.Int +VS.RAB.AttEstabPS.Bkg)) < 0.5%

NOTECOUNTERs marked in blue above are not suggested to show to the customer.

Downlink Loading EvaluationTCP is used to assess the downlink power consumption, which represents the downlink loading status. Evaluation of TCP power is helpful to avoid the congestion due to the insufficient power in downlink.Please be aware that the big TCP utility ratio may be caused also by the bad coverage. Coverage problem must be eliminated before we come to the conclusion that power resources are not enough because of too much traffic.TCP for R99 services at busy hour (BH), Total TCP both with R99 services and HSPA services at busy hourBHare under assessment here. Principles for the TCP utilization are:1) The mean R99 TCP Utility Ratio should not exceed 70%2) The mean total TCP Utility Ratio ( R99+HSPA+Common channel) should not exceed 70%.3) Congestion caused by insufficient TCP power are less than 0.5%.If 1) is not met, then more carrier or more sites are suggested, if 2) is met, then more research are needed on the HSDPA user perception experiences. If 3) is not met and exist for a long period of time, then expansion may need.Formulas are: R99_TCP_Utility_Ratio = R99_Mean_TCP_in_BH / Configured_Total_Cell_TCPTotal_TCP_Utility_Ratio = Total_Mean_TCP_in_BH / Configured_Total_Cell_TCPWhere, R99_Mean_TCP_in_BH uses counter VS.MeanTCP.NonHSTotal_Mean_TCP_in_BH uses counter VS.MeanTCPConfigured_Total_Cell_TCP is from configuration file.And make the failures statistics which are caused by insufficient power, the counter are:VS.RRC.Rej.DLPower.CongVS.RAB.FailEstabCS.DLPower.CongVS.RAB.FailEstabPS.DLPower.CongCongestion ratio caused by insufficient TCP power can be calculated and evaluated by following:(VS.RRC.Rej.DLPower.Cong / VS.RRC.AttConnEstab.Sum) Cells Number per NodeB * 15, that means only codes expansion cannot meet the requirement anymore, more carrier or NodeB are required in this case.

Iub transmission limited caseAlso, if network is only Iub transmission bandwidth limited, the following expansion method is suggested:Iub_bandwidth_required = Iub_bandwidth_used/Iub_expansion_factorWhere, Iub_bandwidth_required is the final Iub bandwidth configuration.Iub_bandwidth_used is the Iub transmission bandwidth already used, which is detailed in section 2.5.Iub_expansion_factor is the Iub utilization ratio expected, at least 0.6 is suggested due to Huaweis experiences.

Expanion suggestion for RF resources limited scenarioSolutions are detailed in this section for the case of RF resource is limited. Solve coverage problem in expansionIf the coverage is not good, adding more sites (macro sites or micro sites) is the only way to solve the problem. In the suburban or rural area, improve the coverage by increasing the transmit power (e.g. from 20W/carrier to 40W/carrier) is also a possible solution. But this solution still cannot solve coverage problem if network is uplink coverage limited. Solve capacity problem in expansionNew features (e.g. Dynamic CE allocation for HSUPA, SRB over HSPA, HSPA+, etc) introduction is suggested to be the first priority to release capacity pressure. New feature introduction is easy to introduce and has the lowest cost.Adding more carriers is suggested to be the second priority solution if frequency resources are available. Adding carriers is an efficient way to improve the capacity.Add macro/micro sites is also a expansion solution if adding more carrier is not applicable.Please be aware that due to Huaweis research, adding transmit power in dense urban / urban is much less effective than adding new carrier or micro-cell. The capacity improvement by adding power from 20W to 40W in dense urban and urban area is around 5% or even less. Adding carrier power could solve part of the coverage and capacity problem in Suburban and Rural area, but still is not an efficient way compare to adding sites.

In the following section, we will give a example of the whole network expansion.Target Network Traffic RequirementThe traffic increase and network expansion strategy in 2 years for operator is shown below. HSPA+ is introduced to improve the cell capacity and user experiences in Year 1 and Year 2.Table 31 Traffic increase and network expansion for operators target networkItemNowYear1Year2

Cumulative Subscribers177402573339601

Voice Traffic growth rate37437150%180%

VP Traffic growth rate700120%130%

Cumulative new sites0100200

Ratio of 2nd carrier sites20%50%80%

Ratio of HSPA+ 64QAM060%100%

Target Network ConfiguationAccording to current radio resource utility ratio and target network scale, radio resource requirement could be analyzed and calculated in advance for network expansion design.Traffic increase predicted by operator and the traffic/configuration information sampled from the existing network are used to make the calculation. Huawei professional UMTS network expansion planning tools can support the high efficiency calculation.Final NodeB ConfiguationThe network needs to be re-planned with the exact traffic requirements in the future. More carriers or sites may need to address the traffic increase. If more sites are introduced, then the CE configuration or Iub configuration for each NodeB need to be re-considered.In operators network, 1 more carriers are introduced to meet the capacity requirement. Also few new sites are introduced to meet the coverage and capacity requirement in part of the area, the final configuration is shown below:Table 32 List of New Cells introducedRNC IDNode B NameNew Cell IDNodeB configuration after new cells introduced

181UPENDT013762 S222

181UPECRU043183 S222

181UPECRU013155

181UPENDT032085

181UPEEPH022048

185UCECUC032535

185UCEPAR092512

185UCEEDS082408

185UCEPIC042390

185UCEPAR033499

.

Table 33 List of New Sites introducedRNC IDNew NodeB NameNew NodeB Configuration

181UPENDN08S111

181UPECRN 04S222

181UPECRN01S111

181UPENDN03

181UPEEPN02

185UCECUN03

185UCEPAN09

185UCEEDN08

.

Final CE ConfiguationAccording to the evaluation result in 2.5.1 , UL CE is the bottleneck in the network. HSDPA wouldnt consume any CE due to HUAWEIs separate chipset design for HSDPA.After introducing the new carrier and new NodeB in the network, the final CE configuration for each NodeB is shown below.Table 34 Final CE configurationRNC IDNode B NameNodeB IDOld CE configurationNew CE configuration

181UPENDT01376 128384

181UPECRU043183 128384

181UPECRU013155 128384

181UPENDT032085 128384

181UPEEPH022048 128384

185UCEEDN084770128

Iub Transmission ConfigurationThe final Iub transmission configuration is shown in the following table:Table 35 Final Iub configurationRNC IDNode B NameNodeB IDOld Iub configurationNew Iub ThroughputNew IubConfiguration

181UPENDT013761.2Mbps3.5Mbps2E1

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