BTC_Bahamas_3G_Network_Audit_v1 (2).pdf

3g Network audit

BTC Bahamas

September 2014

BTC Bahamas 3G Network Audit | Commercial in confidence | 2014-09-19 | Page 2

Overview

KPIs Analysis

Parameters analysis

Summary

Annex

contents


overview


introduction

This report presents a 3G RAN parameters audit for BTC Bahamas.

Current parameterization was analyzed and recommendations provided where appropriate.

Sectors analyzed belong to RNCBAH1 and RNCBAH2 RNCs.

Network configuration analysis is based on data from 16th of september.

Performance analysis is based on data from 1st to 18th of september for all the optimization area.


Area Scope

660 cells, 225 sites, 2 RNCs.

2nd carrier nearly fully deployed in New Providence (NP) Island.

The 2nd carrier cells in AB (2 cells) and GB (4 cells) are 1900 cells. All

the other cells are 800.


KPI Analysis


In average, HSDPA traffic is more than 97% of total PS DL traffic and EUL traffic more

than 77% of total PS UL traffic.

Traffic


Accessibility RRC and RAB kpis for CS and PS are at acceptable levels.

Accessibility


Retainability for CS and PS is ok.

The majority of the speech drops is due to IRAT HO failures.

Retainability


HSDPA is mainly HS-SCCH code limited.

HSDPA


The IRAT HO failure rate is more than 5% and the activity rate more than 40% which is too high.

HO Performance


Parameters analysis


There are 6 cells with maximumTransmissionPower < maxDlPowerCapability. These cells are WAB124A, WEL314A/B, WLI323A/B/C. Adjustment is needed to fully use the

PA power capability.

Proposal: Set maximumTransmissionPower equal to maxDlPowerCapability for these 6 cells. maximumTransmissionPower can be optimized per cell, by

setting its difference wrt maxDlPowerCapability in a range [-2, 0] dB.

maximumTransmissionPower / maxDlPowerCapability

POWER

Tuned with xParameters


CPICH power: values mainly distributed between 34 and 37 dBm,

majority at 34 dBm.

CPICH load: pcpich % wrt min (maximumTransmissionPower,

maxDlPowerCapability). Values mainly

distributed between 4% and 10%, the

majority being at 4%.

Proposal: A per-cell CPICH power optimization in the range [5, 10]%.

primaryCpichPower

POWER



maxFach1Power defines the power used for rrcConnectionSetup message transmission from the NodeB to the mobile in the call establishment phase.

Depending on the environment, an increment in the transmission power of that

channel can improve the accessibility without impacting in average power

consumption (only 1 message is affected).

The values are as follows:

Proposal: Optimize this parameter in a range [1.5, 4] dB.

maxFach1Power

POWER


maxFach1Power

(dB) # of cells

1.8 226

4 386

5 48


These parameters define the maximum power for common channels relative to primary CPICH power.

Field tests prove that default values are high and use excessive resources, depending on radio environment.

Proposal: Optimization of the power allocated to these channels, at cell level, in order to improve EcNo and save power resources that will be translated into

higher HSDPA throughput and better drop rate, without any impact on coverage

footprint.

Common Channels Power

POWER

Parameter Current / Default (dB) Proposed

range (dB)

primarySchPower -1.8 [-3, -1]

secondarySchPower -3.5 [-5, -2]

bchPower -3.1 [-5, -3]

aichPower -6 [-8, -5]

pichPower -7 [-9, -5]

pchPower -0.4 [-4, 0]

maxFach2Power 1.5 [-0.5, 4]



minPwrMax / interPwrMax / maxPwrMax min/inter/maxPwrMax set the maximum power that different RABs can use.

A new schema for these parameters could save power, slightly improve RF environment and increase HSDPA throughput, specially in areas with high load of

HSDPA users.

The idea is to change the bitrates that define what falls into min/inter/maxPwrMax so that the A-DCH (R99 channel associated to HS) and high bitrate R99 DL RABs

use less power.

All the cells are currently using the default values for all the parameters except for minPwrMax for which the distribution is as follows:

Note that voice calls will still use up to +3 dB.

POWER

Parameter Default Proposal

minimumRate 1590 370

interRate 7760 1590

maxRate 40690 40690

minPwrMax 0 -15

interPwrMax 38 30

maxPwrMax 48 30


minPwrMax

(dB) # of cells

0 165

1.5 3

2 95

3 397


minPwrRl minPwrRl sets the minimum power per RL.

It is set as follows:

Proposal: Optimize it in a range [-18, -12].

POWER


minPwrRl

(dB) # of cells

-15 645

-12 15


dlInitSirTarget, along with the measured EcNo, SF and CPICH power, determines the initial downlink DPDCH power, related with maxFach1Power.

Current values are 2.8dB for RNCBAH1 and 4.1dB for RNCBAH2. However, fields tests proved its possible to further decrease it and reduce the interference without degradation.

Proposal: Decrease the value for RNCBAH2. The recommended value for this parameter is 2.5dB.

pO3 sets the power offset for the pilot bits and pO2 sets the power offset for the TPC bits.

They are set as follows:

Proposal: Set pO3 to 0dB and pO2 to 1.5dB for RNCBAH2.

dlInitSirTarget / pO3 / pO2

POWER

Parameter RNCBAH1 RNCBAH2

pO3 0dB 3dB

pO2 1.5dB 3dB


pwrAdm / pwrOffset / dlCodeAdm

pwrAdm defines the power threshold used by the Admission Control (AC) above which only R99 incoming HOs will be able to access the cell.

pwrAdm and pwrOffset are set as follows:

dlCodeAdm is the admission limit based on the DL ovsf code tree usage. It is set as follows:

Proposal: Optimize pwrAdm in a range [80, 95] (pwrAdm+pwrOffset = 99%).

ADMISSION

dlCodeAdm # of cells

90 2

95 623

97 29

99 6


pwrAdm pwrOffset pwrAdm + pwrOffset # of cells

95 4 99 208

90 9 99 436

90 5 95 9

75 9 84 5

75 4 79 2


sf8Adm / sf16Adm / sf32Adm

These parameters set the maximum number of users with a specific R99 DL RAB based on the spreading factor used.

Current configuration is:

Proposal: Set sf8Adm to 0 and sf32Adm to 32 for all the cells.

ADMISSION

Parameter RAB Related Value # Cells

sf8Adm PS384 DL

0 651

2 1

3 3

8 5



sf16Adm PS128 DL

0 409

1 157

4 83

6 4

16 7 Parameter RAB Related Value # Cells

sf32Adm PS64 DL

6 2

12 641

24 1

32 16


sf4AdmUl / sf8AdmUl / sf16AdmUl

These parameters set the maximum number of users with a specific R99 UL RAB based on the spreading factor used.

Current configuration is:

Proposal: Set sf4AdmUl to 0 and sf16AdmUl to 50 for all the cells.

ADMISSION

Parameter RAB related Value # Cells

sf4AdmUl PS384 UL

0 651

2 1

3 3

8 2

1000 3



sf8AdmUl PS128 UL

0 171

2 480

4 1

6 3

8 3

16 2 Parameter RAB Related Value # Cells

sf16AdmUl PS64 UL 16 3

50 657


maxNumHsdpaUsers defines the maximum number of HS users in each cell by license.

hsdpaUsersAdm limits the new establishments. Above that value only accessing by cell reselection will be allowed.

hsdpaUsersAdm is aligned to maxNumHsdpaUsers for all the cells.

maxNumHsdpaUsers / hsdpaUsersAdm

ADMISSION


maxNumEulUsers defines the maximum number of EUL users in each cell by license.

eulServingCellUsersAdm is the admission threshold for the number of E-DCH users per cell.

eulServingCellUsersAdm is aligned to maxNumEulUsers for all the cells.

maxNumEulUsers / eulServingCellUsersAdm

ADMISSION


dlHwAdm and ulHwAdm define the Admission Control threshold for hardware resource utilization, both in DL and in UL.

The setting is as follows:

Proposal: Set dlHwAdm and ulHwAdm to 99% on all the NodeBs.

dlHwAdm / ulHwAdm ADMISSION

dlHwAdm # of sites

95 43

99 143

100 34

ulHwAdm # of sites

95 43

99 143

100 34


numHsScchCodes / cqiAdjustmentOn /

featureStateHsdpaFlexibleScheduler

numHsScchCodes defines the number of HSDPA users that can be scheduled simultaneously in the same TTI.

The distribution is as follows:

cqiAdjustmentOn allows the NodeB to tune the CQI in order to achieve HS retransmission rate close to 10% aiming to maximize HSDPA throughput.

It is disabled on 14 cells.

HS Flexible Scheduler feature allows code multiplexing and HS-SCCH power control.

It is disabled on 3 NodeBs.

Proposal: Optimize numHsScchCodes in a range [2, 4]. Activate cqiAdjustmentOn and HS Flexible Scheduler respectively on the cells and NodeBs where it is

disabled.

HSDPA


numHsScchCodes # of cells

1 103

2 550

3 7


numHsPdschCodes / maxNumHsPdschCodes

/ featureStateHsdpaDynamicCodeAllocation

numHsPdschCodes defines the minimum number of SF16 codes for HS-PDSCH assigned as fixed for the HSDPA service.

The distribution is as follows:

maxNumHsPdschCodes defines the maximum number of SF16 codes that can be used for HS-PDSCH.

3 cells have maxNumHsPdschCodes = 5. .

dynamicCodeAllocation feature allows to dynamically assign SF16 from the minimum up to the maximum while guaranteeing R99 traffic priority.

This feature is disabled for 6 cells.

Proposal: Optimize numHsPdschCodes in a range [1, 5]. Set maxNumHsPdschCodes to 15 and dynamicCodeAllocation to true on all the cells.

HSDPA


numHsPdschCodes # of cells

1 37

2 54

4 561

5 8


codeThresholdPdu656 / queueSelectAlgorithm

codeThresholdPdu656 defines the threshold for determining when to use the RLC PDU size of 656 bits. 656 bits are used if codeThresholdPdu656 < numHsPdschCodes.

It is set as follows:

queueSelectAlgorithm specifies the algorithm for HSDPA resources assignment between users.

It is set to 1 (proportional fair medium) on 571 cells and to 0 (round robin) on 59 cells.

Proposal: Set codeThresholdPdu656 to 0 on all the cells to ensure using PDU656 and queueSelectAlgorithm to 1 on all the cells.

CQI factor Scheduling weight factor Average rate factor Delay factor Air rate factor Retrans-mission factor

0 Round Robin Time based X X X

1 Proportional fair medium fairness X X X X

2 Proportional fair high fairness X X X X

3 Proportional fair low fairness X X X X

4 Maximum CQI X X X

5 Equal rate X X X

queueSelectAlgorithm

HSDPA

codeThresholdPdu656 # of cells

0 14

1 141

6 505


hsMeasurementPowerOffset

HSDPA

The value of the MPO defines the power that the Node B is supposed to use for each user and the power that the UE expects to be transmitted.

P_hs = primaryCpichPower + hsMeasurementPowerOffset

An excessive value for the MPO parameter means a high consumption of resources for an only user, and so wasting the possibility of the multi-user transmission. In addition, requesting too much resources might

lead to power starvation and a final user throughput reduction.

Likewise, using an excessive low value when the CQI distribution is not adjusted for the optimum BLER value of 10% also could impact in the throughput since the transport block size assigned could be lower

than the optimum one.

Current setting is showing MPO = 8 dB on 581 cells and 6 dB on 79 cells.

Proposal: Optimize MPO per cell in a range [4, 8].



hsToDchTrigger

This set of parameters indicate whether a reconfiguration from HSDPA to R99 is allowed or not.

All the subsets of this parameter (servHsChangeInterRnc, servHsChangeIntraRnc, poorQualityDetected, changeOfBestCellIntraRnc and changeOfBestCellInterRnc) are

deactivated on both RNCs which is ok.

HSDPA


RACH configuration:

constantValueCprach: is included in the formula that calculates the initial power for RACH preambles transmission

P_PRACH = L_PCPICH + RTWP + constantValueCprach with [L_PCPICH --> Path Loss] & [RTWP --> UL Interference ]

powerOffsetP0: defines the step up for RACH preambles

preambleRetransMax: defines the number of RACH preambles retransmissions

powerOffsetPpm: defines the power offset between the RACH message and the last preamble sent

Proposal: Optimize constantValueCprach in the range [-27, -15] and powerOffsetPpm in the range [-5, 2]. Set powerOffsetP0 and preambleRetransMax

respectively to 1 and 32 on all the cells.

RACH related

UPLINK

Parameter Value # of cells

constantValueCprach -27 94

-19 566

powerOffsetP0

1 177

2 480

3 3

preambleRetransMax 8 32

32 657

powerOffsetPpm -4 594

-1 66



This parameter is intended to react faster to an increased interference level from neighboring cells. A higher value provides quicker reaction time and less interference, but

less EUL throughput when the interference from other cells is low.

Current configuration is showing the default value (10%) on all the cells.

Proposal: Avoid any conservative margin, by setting eulMinMarginCoverage = 0 across the network.

eulMinMarginCoverage

UPLINK


eulMaxOwnUuLoad and eulMaxRotCoverage define the maximum noise allowed to be introduced by HSUPA service. The first one is an estimation of the noise introduced by the

R99 traffic created by the cell itself. The second is based on a real measurement of the

total UL noise.

As the first limit is an estimation and the second is a real measurement, we consider that the second parameter should be used as a general control of the noise allowed to HSUPA

and eulMaxOwnUuLoad should be set in a not limiting way.

Proposal: Align eulMaxOwnUuLoad to eulMaxRotCoverage for all cells.

eulMaxOwnUuLoad / eulMaxRotCoverage

UPLINK

eulMaxOwnUuLoad eulMaxRotCoverage # of cells

30 100 152

80 100 426

100 100 52


eulSlidingWindowTime sets the time window size use to compute the noise floor.

It is set to 72000 on 609 cells and to 1800 on 21 cells.

eulMaxShoRate defines the maximum throughput allowed for an EUL service when the UE is in SHO.

It is set to 5760 on all the Node Bs.

Proposal: Set eulSlidingWindowTime to 72000 on all the cells.

eulSlidingWindowTime / eulMaxShoRate

UPLINK


sirMax / sirMaxTti2 limit the uplink SIR for EUL 10ms and 2ms users.

Current setting: sirMax = 12 dB on RNCBAH1 and 10 dB on RNCBAH2. sirMaxTti2 = 17.3 dB on both RNCs.

Proposal: Recommended setting for sirMax and sirMaxTti2 is respectively 10 dB and 12 dB.

transmissionTargetError / transmissionTargetErrorTti2 steer the uplink outer loop power control through the modulation of the SIR target for EUL users.

Current setting: 10%/15% on RNCBAH1 and 1%/2% on RNCBAH2.

Proposal: Recommended setting for transmissionTargetError and transmissionTargetErrorTti2 is respectively 100 (10%) and 50 (5%).

sirMax / transmissionTargetError

UPLINK


UTRAN RL failure detection is controlled by the Radio Connection Supervision (RCS) and Radio Link Set (RLS) Supervision functions. After receiving nOutSyncInd consecutive

frames, UTRAN starts timer rlFailureT. If rlFailureT expires, the RLS function considers

the connection as out-of-sync and reports RL Failure to SRNC.

nInSyncInd defines the number of frames to be considered for in-sync detection and then, reset nOutSyncInd and rlFailureT count. Its hardcoded to 1 frame.

Current settings:

Proposal: Align rlFailureT to 3s and nOutSyncInd to 200 on all the cells.

nOutSyncInd / rlFailureT / nInSyncInd


rlFailureT 1 s 10

3 s 650

nOutSyncInd 10 10

200 650

SYNCHRONIZATION



cfnOffsetMarginFirstRabEst and cfnOffsetMarginSrbDchDl define a temporary frames margin, applied over the calculated by the RNC, to synchronize the establishments and

radio reconfigurations between the UE and the RNC for RAB and SRB.

The RNC assesses a margin taking into account only 1 RLC PDU retransmission, so in case of more retransmissions maybe there could be not enough time to establish the

connection/reconfiguration, avoiding connections to drop.

Proposal: Improve DCR by increasing cfnOffsetMarginFirstRabEst = 60 and cfnOffsetMarginSrbDchDl = 60.

UTRAN RL failure detection is controlled by the Radio Connection Supervision (RCS) and Radio Link Set (RLS) Supervision functions. After receiving nOutSyncInd consecutive

frames, UTRAN starts timer rlFailureT. If rlFailureT expires, the RLS function considers the

connection as out-of-sync and reports RL Failure to SRNC. When RL Failure is received

on all radio links in the connection, the SRNC starts timer dchRcLostT and when it

expires the connection is considered lost by RCS and the call is counted as dropped.

Proposal: Keep dchRcLostT = 100 and hsDschRcLostT = 100.

cfnOffsetMarginFirstRabEst /

cfnOffsetMarginSrbDchDl / dchRcLostT

SYNCHRONIZATION


Channel Switching These parameters control the timers and thresholds for channel switching and

reconfigurations:

Parameter All RNCs

DCH to FACH

downswitchThreshold 0

downswitchTimerThreshold 8

downswitchTimer 10

hsdschInactivityTimer 2

FACH to IDLE

inactivityTimer 3

FACH to DCH

dlRlcBufUpswitch 500

ulRlcBufUpswitch 256

UPSWITCHING DCH-DCH

bandwidthMargin 90

bandwidthMarginUl 90

upswitchTimer 5

upswitchTimerUl 5

DOWNSWITCHING DCH-DCH

dlDownswitchBandwidthMargin 80

dlThroughputDownswitchTimer 20

ulDownswitchBandwidthMargin 80

ulThroughputDownswitchTimer 20

MultiRAB

dlRlcBufUpswitchMrab 0

ulRlcBufUpswitchMrab 8

downswitchTimerSp 2

downswitchTimerUp 60

CHANNEL SWITCHING


Multi-RAB connections with high UL bitrate (> 64 kbps) have their SRB less protected and may suffer from more drops.

It is recommended to disable UeRc (RABcombination) 20, 36, 38, 39, 60 and 76 in order to improve DCR.

All these UeRc are disabled on the 2 RNCs except for UeRc 39 which is active on RNCBAH2.

RAB Handling

UeRcId RAB Description

20 Conv. CS speech 12.2 + Interact. PS (384/HS)

36 Conv. CS speech 12.2 + Interact. PS (64/128)

38 Conv. CS speech 12.2 + Interact. PS (64/384)

39 2* Interact. PS (64/128)

60 Conv. CS Speech 12.2 + Interact. PS (128/HS)

76 Conv. CS Speech 12.2 + 2* Interact. PS (128/128)

RAB HANDLING


qQualMin / qRxLevMin

Through these parameters we can set the minimum quality and signal level needed to access the 3G network.

Current values are as follows:

Regarding the interaction with the GSM network, i.e. with fddQMin (minimum quality value to reselect from 2G to 3G), the following rule should be respected:

qQualMin + sRatSearch < fddQMin

fddQMin is mainly equal to 7 (-12 dB) across the network.

Since qQualMin is in majority -18 and sRatSearch in majority 2, there is enough hysteresis between both networks to avoid ping-pong issues.

Proposal: Align qQualMin at -18 dB for all the cells and optimize qRxLevMin in the range [-115, -101] dBm.

idle


Carrier qQualMin # of cells

1

-18 508

-16 1

-15 3

2

-20 6

-18 100

-15 42

Carrier qRxLevMin # of cells

1 -115 174

-105 338

2

-115 6

-105 97

-101 39

-91 6


sIntraSearch / sInterSearch / sRatSearch

These parameters are used to manage the threshold to start the measurements for reselection in intra/inter-frequency and from 3G to 2G in IDLE mode.

Measurements are activated when: CPICH_EcNo sxSearch + qQualMin

sRatSearch is equal to 2 for the majority of the cells (2 for 649 cells and 4 for 11 cells). In order to keep as much traffic as possible in the 3G network, we suggest to go down with

the iRAT Reselection threshold (qQualMin + sRatSearch).

Proposal: Optimize sRatSearch in the range [0, 2].

For intra-freq measurements, sIntraSearch is set to 0 (always measure) on all the cells.

For inter-freq measurements, sInterSearch is set as follows:

To save UE battery, it would be better not to always perform reselection measurements.

Proposal: Set sIntraSearch = sInterSearch = 10 dB (22 in OSS) or optimize them, sIntraSearch in a range [10, 14] dB and sInterSearch in a range [8, 14] dB.

idle


sInterSearch # of cells

0 (always) 82

21 (8dB) 438

24 (14dB) 98

25 (16dB) 42


qOffset2sn / qHyst2 / treSelection

Those parameters define the mobility of UEs in IDLE mode, by setting the hysteresis, the offset (at neighbor level) and the time to trigger from which the mobile is allowed to

change the cell.

Current configuration on the network is as follows:

Proposal:

Align all cells to qHyst2 = 2 and treSelection = 2 (recommended value for treSelection is 1s).

Optimize qOffset2sn in a range [-3, 3] (for inter-freq adjacencies) for better load balancing between carriers.

idle


Adj Type qOffset2sn # of adj

ADJI

0 7079

5 1

-5 1

7 36

-7 35

ADJS

0 8498

7 34

-7 33


qHyst2 2 651

4 9

treSelection 2 654

1 6


Current parameters configuration is the following:

Proposal: Ensure all carrier 1 (resp. carrier 2) cells have hoType = 1 (resp. hoType = 0). Optimization of

2d thresholds for carrier 1 cells in a way to increase

the 3G usage and reduce the IRAT HO rate: 2d Rscp

in a range [-110, -105] dBm and 2d Ecno in a range

[-15, -13] dB.

usedFreqThresh2dRscp / usedFreqThresh2dEcno

HO

RNC related parameters RNCBAH1 RNCBAH2

usedFreqRelThresh2fEcno 1dB 1dB

usedFreqRelThresh2fRscp 3dB 3dB

hysteresis2d 0 0

hysteresis2f 0 0

hysteresis3a 0 0

timeToTrigger2dEcno 640ms 320ms

timeToTrigger2dRscp 640ms 320ms

timeToTrigger2fEcno 1280ms 1280ms

timeToTrigger2fRscp 1280ms 1280ms

utranRelThresh3aEcno 1 -1

utranRelThresh3aRscp 2 -3

usedFreqRelThresh4_2bEcno -1 -1

usedFreqRelThresh4_2bRscp -3 -3

gsmThresh3a -95dBm -95dBm


Carrier usedFreqThresh2dRscp # of cells

1

-105 442

-100 64

-95 6

2

-107 6

-105 98

-100 40

-95 4

Carrier hoType # of cells

1 1 511

0 1

2 1 21

0 127

Carrier usedFreqThresh2dEcno # of cells

1

-13 492

-12 12

-10 8

2 -15 6

-13 142


serviceOffset2dEcno and serviceOffset2dRscp define an offset at RNC and RAB level, to be added to the 2d events thresholds.

These offsets are equal to 0 for all the RABs on both RNCs.

Proposal: Set serviceOffset2dEcno = -20 and serviceOffset2dRscp = -50 for pure PS RABs to avoid PS IRAT HO. The pure PS RABs activated are UeRc 21, 26, 39, 53, 54, 67, 68, 69.

serviceOffset2dEcno / serviceOffset2dRscp

HO


reportingRange1a and reportingRange1b

They determine the SHO windows.

Current values are the proper ones.

timeToTrigger1x / hysteresis1x / hsTimeToTrigger1d / hsHysteresis1d

They define the time that radio conditions have to fulfill before an event 1a/1b/1c/1d are triggered

reportingInterval1a/1c

They are used to configure the interval of periodical

reporting of an event 1a or event 1c in case of 'cell

addition failure' or 'cell replacement failure'.

They are set to 3 (1 s) on both RNCs.

It is recommended to deactivate this periodical

event reporting by setting these parameters to 0.

HO

Parameter RNCBAH1 RNCBAH2

timeToTrigger1a 320ms 320ms

timeToTrigger1b 640ms 640ms

timeToTrigger1c 320ms 320ms

timeToTrigger1d 2560ms 2560ms

hysteresis1a 2dB 0dB

hysteresis1b 2dB 0dB

hysteresis1c 4dB 1dB

hysteresis1d 7.5dB 7.5dB

hsTimeToTrigger1d 640ms 640ms

hsHysteresis1d 3dB 1dB

Active Set Control (I)

Parameter Both RNCs

reportingRange1a 3 dB

reportingRange1b 5 dB


individualOffset is added to the measured quantity before the UE evaluates if a SHO event has occurred.

This parameter is powerful to increase SHO Addition window for cells suffering from drops.

Current values are distributed as follows:

Proposal: Cell-level optimization in the range [-0.5, 2.5] dB.

Active Set Control (II) HO


individualOffset # of cells

-1dB 1

-0.5dB 6

0dB 652

3dB 1


IFLS

DCH and HS IFLS are not activated on both RNCs.

Parameters are set as follows:

Coverage relations are only defined for cells of 8 NodeBs with all relationCapability attributes (dchLoadSharing, hsCellSelection and hsLoadSharing) activated.

iflsMode is set to 2 (RAB_EST_AND_UPSWITCH_ATT) on all the cells.

It is suggested to define all coverage relations between cells of bi-carrier sites and to define a load balancing strategy by activating DCH and HS IFLS.

LS



dchIflsThreshPower 0 660

dchIflsThreshCode

0 630

65 30

dchIflsMarginPower 0 660

dchIflsMarginCode 0 660


hsIflsThreshUsers

0 612

10 48

hsIflsMarginUsers 0 660

hsIflsHighLoadThresh 100 660

hsIflsSpeechMultiRabTrigg 1 660


pathlossThreshold 170 660


tCell

It is used by the NodeB in order to shift the synchronization channels (P-SCH and S-SCH) among the sectors of the site, so the signals are not overlapped and they are

managed by the UEs more easily.

14 cells have repeated tCell parameter within the same site and carrier. WBI199A/B/C, WGB056C/D, WGB056G/H, WNP006D/E/F, WNP022D/F, WNP048B/C.

Proposal: Correct the tCell for these cells.

MISCELLANY


Summary


One-shot proposal (1/2)

Level Parameter Before After Reason/Benefit

CELL minPwrMax/interPwrMax/maxPwrMax

minimumRate/interRate

0/3.8/4.8 dB

15.9/77.6

kbps

-1.5/3/3 dB

3.7/15.9

kbps

- Increase power for Speech (improve retainability) - Use less power for A-DCH and reduce non-HS power

consumption mainly for high loaded HSDPA cells (more

power will be available for HS and should lead to throughput

improvement)

- Lower power for high rate PS R99 (maxPwrMax reduction)

so more power for HS.

CELL maximumTransmissionPower <

maxDlPower

Capability

=

maxDlPowe

rCapability

Make use of the full PA power capability

CELL sf8Adm/sf4AdmUl 0/0 Avoid high resource consumption with PS DL 384 and PS UL

384 usage

RBS dlHwAdm/ulHwAdm 99%/99% Better utilization of the HW resource

CELL hoType Ensure all carrier 1 cells have hoType = 1 (GSM) and carrier

2 cells hoType = 0 (IF)

CELL maxNumHsPdschCodes 5 15 Better HSDPA performance

CELL cqiAdjustmentOn OFF ON Better HSDPA performance

CELL featureStateHsdpaDynamicCodeAllocation OFF ON Better HSDPA performance

CELL codeThresholdPdu656 > 0 0 Better HSDPA performance

The following table contains the list of one-shot changes to perform at the start of the optimization, to set some parameters to the recommended values and/or to adjust

some cells parameters values to baseline.


One-shot proposal (2/2) Level Parameter Before After Reason/Benefit

CELL queueSelectAlgorithm 0 1 Better HSDPA performance

RBS featureStateHsdpaFlexibleScheduler OFF ON Better HSDPA performance

RBS featureState16Qam/featureState64Qam 0/0 1/1 Better HSDPA performance

CELL eulMaxOwnUuLoad <

eulMaxRo

tCoverage

=

eulMaxRot

Coverage

More power for EUL scheduling

CELL powerOffsetP0 2 or 3 1 Recommended value

CELL preambleRetransMax 8 32 Baseline

CELL qQualMin -18 dBm Align qQualMin to one value for all cells to properly optimize IRAT,

Intra and Inter Freq reselection thresholds

CELL qHyst2 4 dB 2 dB Baseline

CELL treSelection 1 s 2 s Baseline

CELL rlFailureT / nOutSyncInd 1 s / 10 3 s / 200 Baseline

RNC serviceOffset2dEcno/Rscp for PS Rabs 0/0 -20/-50

or -3/-5

Avoid completely or reduce PS IRAT HO

RNC dlInitSirTarget 4.1 dB 2.5 dB Save power

RNC sirMaxTti2 17.3 dB 12 dB Reduce UL Noise (better retainability)

RNC transmissionTargetError/transmissionTa

rgetErrorTti2

10%/5% Recommended values

RNC cfnOffsetMarginFirstRabEst/

cfnOffsetMarginSrbDchDl

0/0 60/60 Improve retainability

RNC pO2/pO3 3/3 dB 1.5/0 dB Save power


xParameters settings (1/2)

Level Parameter Min Max Max Step

Up

Max Step

Down

Comment

Cell pwrAdm 80 95 2 2

Cell pwrOffset N.A. N.A. Accordingly with pwrAdm + pwrOffset =

99%

Cell maximumTransmissionPower maxDlPowerCapa

bility - 2

maxDlPowerCapa

bility 0.5 0.5

Cell minPwrRl -18 -12 1 1

Cell primaryCpichPower 30 38 0.5 0.5 Min (resp. Max) pcpich is 5% (resp. 10%)

of min (maximumTransmissionPower,

maxDlPowerCapability) Cell primaryCpichPower (%) 5 10 N.A. N.A.

Cell maxFach1Power 1.5 4 0.5 0.5

Cell qRxLevMin -115 -101 2 2

Cell sRatSearch 0 2 2 2

Cell usedFreqThresh2dEcno -15 -13 1 1

Cell usedFreqThresh2dRscp -110 -105 1 1

Cell hsMeasurementPowerOffset 4 8 1 1

Cell numHsScchCodes 2 4 1 1

Cell numHsPdschCodes 1 5 1 1

Cell individualOffset -0.5 2.5 0.5 0.5

Cell sInterSearch 8 14 1 1

Cell sIntraSearch 10 14 1 1

Cell constantValueCprach -27 -15 1 1

Cell powerOffsetPpm -5 2 1 1

The following table is a proposal for the parameters to be optimized with xParameters with the optimization ranges and steps.


xParameters settings (2/2)

Level Parameter Min Max Max Step

Up

Max Step

Down

Comment

Cell primarySchPower -3 -1 1 1

Cell secondarySchPower -5 -2 1 1

Cell bchPower -5 -3 1 1

Cell aichPower -8 -5 1 1

Cell pichPower -9 -5 1 1

Cell pchPower -4 0 1 1

Cell maxFach2Power -0.5 4 1 1

Adj qOffset2sn -3 3 1 1


ANNEX


Inconsistencies list

This file contains the lists of cells with inconsistencies (to be checked/adjusted)

Date post:	01-Oct-2015
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BTC_Bahamas_3G_Network_Audit_v1 (2).pdf

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