WCDMA Radio Optimization

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CCoonntteennttss Radio planning optimization ................................................ 3-14

Quality of Service .............................................................. 15-22

Measurement and statistics collection ............................... 23-29

KPI .................................................................................... 30-32

Accessibility....................................................................... 33-38

Retainability....................................................................... 39-44

Integrity ............................................................................. 45-47

HSDPA-HSUPA ................................................................ 48-55

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RRaaddiioo ppllaannnniinngg ooppttiimmiizzaattiioonn

- 4 -

AAnntteennnnaa hheeiigghhtt � Since WCDMA performance is interference limited the cell

dominance areas should be kept as controlled as possible � lf the antenna is located “too high” (no proper tilting) then

� The cell gathers more traffic and external interference and thus the “effective” capacity is decreased

� Produced interference decreases the capacity of the surrounding network

� Also surrounding network’s service probability is negatively effected

AAnntteennnnaa aazziimmuutthh � Natural obstacles and buildings should be used to create good

dominance areas for WCDMA cells � This improves the SHO performance and decrease interference

AAnntteennnnaa hheeiigghhtt ssiimmuullaattiioonn � When re-using the GSM sites, analysis should be made

whether the UMTS antennas should be positioned lower � This analysis is done with simulations and visiting the site

locations in practise

� Example of a UMTS cell, that is naturally bordered (wall effect) by buildings

Part of network reused few +40meter GSM antenna heights

High UMTS antenna positions lowered to 25-35m

Dominance areas become clear, so less interference is introduced and HO performance is better. � Capacity is increased and performance enhanced!

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AAnntteennnnaa ttiilltt � ln addition to antenna height, downtilting is very important

physical means for interference minimizing in WCDMA � Basic rule of designing antenna tilt is that the height of the

antenna should be selected with respect to the wanted amount of cell range

� If the cell range with respect to available antennas and their tilting with a feasible amount of tx-power becomes too large to suit the network plan, then the antenna must be lowered

� According to experience, the analysis should start with the optimum tilting and not by reducing the tx-powers of the cell, which can be optimized after the tiltings are done

AAnntteennnnaa ttiilltt � According to experience even 15 degrees of downtilting is not

impossible (lf the radiation pattern of the antenna supports it), although in practice not very often needed.

� There has also been lot of

discussion of a potential need to change the tilts often during the network lifecycle (even regularly)

� However practice have not

shown such need if the tilts are design well from the start with help from simulations

� But once WCDMA gets

congested this might be given another look (Remote tilts).

h

Horizontal plane

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SSeeccttoorriissaattiioonn � According to simulations and analysis, sectorisation of WCDMA

site helps to improve capacity of the network � However, as permissions for additional antennas are quite hard

to come by, e.g. 6-sector sites might be very rare

� Sectorisation can

increase the capacity if correct beamwidth antennas are selected and SHO properly controlled

MMaasstteerr hheeaadd aammpplliiffiieerr � The MHA can be used

in WCDMA in the uplink direction to compensate for the cable losses and thus reducing the required mobile station’s transmit powers

� Using MHA the performance in uplink can be improved also in WCDMA systems.

� However in practice if the network turns to downlink limited then the MHA won’t help

Antenna 3 dB

Beam width

Other to own cell

interference ratio, i

Served users

Soft handover overhead

UL coverage probability (outdoor to

indoor) For 8/64/144

kbps OMNI CASE

Omni 0.79 240 28% 70/32/40% THREE SECTORS CASE

1200

900

650

1.33 1.19 0.88

441 461 575

39% 35% 34%

85/50/59% 87/55/62% 86/59/62%

FOUR SECTOR CASE 1200

900

650

330

1.72 1.49 1.09 0.92

489 510 604 691

54% 51% 41% 40%

90/62/68% 92/67/72% 92/70/71% 88/65/64%

SIX SECTOR CASE 1200

900

650

330

2.18 1.97 1.43 1.15

593 627 758 880

64% 59% 55% 48%

95/75/79% 96/80/82% 96/80/81% 93/76/76%

Other to own cell

interference ratio, I

Served users in

UL

Served users in

DL

UL coverage probability (outdoor to indoor) for

8/64/144 hbps THREE SECTORED CASE, 65O antenna

No MHA With MHA

0.60 0.61

1038 1064

807 746

93/78/78% 95/82/82%

FOUR SECTTORED CASE, 65O antenna No MHA

With MHA 0.73 0.73

1089 1107

884 846

96/86/85% 98/89/89%

SIX SECTORED CASE, 33O antenna no MHA

with MHA No MHA

4dB cable losses

WITH mha 4 DbN CABLE

LOSSES

0.88 0.90

0.88

0.90

1124 1132

1109

1132

1052 1021

1057

1016

97/87/86% 98/90/90%

95/83/82%

98/90/90%

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MMaasstteerr hheeaadd aammpplliiffiieerr � Increases uplink coverage/capacity in low loaded network � Compensates for feeder and combiner losses in the uplink

direction, increasing coverage for suburban, rural and road sites where antennas are in very high positions and the feeder lines are long

� Allows UEs to reduce transmission power level � With heavily loaded network (i.e. high interference) the benefit

of the mast head amplifier is negligible � Also in downlink limited 3G networks (DL oriented traffic, users

in cell edge, DL tx-power per user low e.g. in for high bit rate indoor users) the usage of mast head amplifier is not justified

� Needs extra space in the masts and increase the wind load

TTrraannssmmiitt ppoowweerr iinnccrreeaassee

MHA is sometimes called as Tower Mounted Amplifier (TMA)

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TTrraannssmmiissssiioonn ppoowweerrss � Default transmission powers are determined by the equipment

vendors. � In initial phase of the planning

� Transmission powers of TCHs and CCHs needs to be set � Maximum UE transmission power is to be defined

� In DL the power tuning between TCHs and CCHs has effect on network performance

� More power to CCHs —> better channel estimation, which improves the Eb/No performance and thus improves coverage

� More power to TCHs —> better capacity � Rule of thumb: 15-20% of DL total power is used for

CCHs � Maximum UE transmission power should be set to 21-24 dBm

(network operation and battery life) � Most important control channel is the common pilot channel

(CPICH)

TTrraannssmmiissssiioonn ppoowweerrss � Also other control channels beside CPICH need power (for

example BCH) to enable correct functioning of the system � All the other common control channels are powered in relation

to the P-CPICH � The goal of allocating power to the common channels is to find

a minimum power level needed for each channel to secure the network operation and to provide the same cell coverage area as with CPICH, but not to waste any capacity left for the traffic channels.

Max power-11 …13dB BCH

Max power-12…-13dB FACH

Max power-11 …12dB SCH

Max power-11 …-13 dB PCH

Max power-10dB CPICH

43 dBm Max power of the Node B

Allocated power Channel

Typical DL power recommendations

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RReeccaallll:: SSoommee ccoonnttrrooll cchhaannnneellss � PCH: Paging channel initiates the communication from network

side � SCH: Synchronization channel � FACH: Forward access channel carries control information to

terminals that are known to be located in the given cell. ls used to answer to the UL RACH message.

� BCH: Broadcast channel carries network specific information to the given cell (random access slots for UL, antenna configuration etc)

� PICH: Paging indicator channel is used to provide sleep mode operation for UE

� AICH: Acquisition indicator channel is used to indicate the reception of RACH

� CCPCH: Primary and secondary common control physical channels (P-CCPCH and S-CCPCH) are physical channels that carry BCH, FACH and PCH.

TTrraannssmmiissssiioonn ppoowweerrss • P-CCPCH transmitted with activity factor 0,9 • S-CCPCH transmitted with activity factor 0,25 • SCHs transmitted with activity factor 0,1 • AICH, PICH and CPICH are transmitted continuously • The BCH is transmitted on the P-CCPCH and FACH and PCH

on the S-CCPCH • The BCH is transmitted on the P-CCPCH continuously expect

during the 256 first chips, when the P-SCH and S-SCh are transmitted we can assume 0,1 activity factor for the SCHs and 0,9 for the P-CCPCH

Channel Allocated power Power out of the total common

channel powers

Power out of the maximum Node B transmission power

(20W) P-SCH 0,331W

S-SCH 0,224W

PICH 0,1W

AICH 0,126W

P-CCPCH 0,245W

S-CCPCH 1,165W

CPICH 1W 31% 5%

All common ch. 3,191W 100% 16%

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CCaarrrriieerr aaddddiittiioonn � Adding a carrier to less transmit power per carrier, if no

additional PA is installed � Additional carrier can also be used for e.g. optimisation of

indoor coverage with clever network planning and parametrisation (not with power reduction)

� Even with less transmit power, there is a capacity gain possible especially for high traffic areas (low cell range)

� Actual gain produced is heavily dependent on the traffic mix

DL Capacity gain Carrier

configuration Dense Urban 350m

Urban 550m

Suburban 1700m

Rural 7km

1C>2C 92% 87% 77% 60% 2C>3C 41% 37% 27% 15%

IInnddoooorr ccoovveerraaggee aassppeeccttss � Most of the UMTS users are indoors.

Therefore good indoor coverage is vital for UMTS success

� In GSM indoor coverage is pretty straightforward to plan. However this is not the case with WCDMA

� Indoor coverage provided from outdoor base stations is highly sensitive to cell load increase in WCDMA

� If outdoor users is given a high-data rate bearer this can result in loss of coverage to users indoors

INDOOR COVERAGE ANALYSIS • Consider different RAB / coverage scenarios • Carefully estimate the effect of cell loading to the coverage • Use repeaters if possible • Assess the need for indoor sites • Carry out real-life verification of the planning

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PPiilloott ppoolllluuttiioonn � Pilot pollution is faced on a certain area when there is no clearly

dominant CPICHs over the others. � The pilot pollution creates an abnormally high level of

interference, which is likely to result in the performance problems

� Increased interference level � Poor service quality, decreased throughput or increased

delay � Decreased service access � Frequent changes in Active Set and potential risk for

unnecessary handovers. � Higher non-controllable load

PPiilloott ppoolllluuttiioonn � The yellow dots represent points where 4-5 CPICHs were

received within 6dB window � As Active Set size is typically 3, in this situation the rest of the

Pilots produce unnecessary interference

PPiilloott ppoolllluuttiioonn � Pilot pollution can be (at least partly) avoided by planning the

CPICH powers and SHO parameters so that throughout the network there is only 2-3 CPICHs available for the UE’s, strong enough to be included in the Active Set.

� All CPICH outside Active Set should be clearly weaker � Antenna design, height and tilt are selected carefully � Balanced UL & DL � SCH/DCH power adjustments

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NNeeiigghhbboouurr cceellll rreellaattiioonnss

� The Monitored Set is also called as a Neighbour List. This list can be defined in network planning and it can be later changed in network optimization.

� The list of neighbours play an important role since WCDMA is interference limited. Insufficient planning of neighbour relations will lead to unnecessary high interference

� E.g. if suitable SHO candidate is not in the monitore set and thus it is not selected to active set then it’s turning to a “pilot poIIuter”

� On the other hand, unnecessary neighbours increase signalling and effects the SHO selection negatively

� Accurate neighbour relations planning is much more important than in GSM

� In GSM it is possible to “hide” cell planning mistakes by frequency planning, in CDMA the such inaccuracies will effect the system capacity

� The effort saved in frequency planning is spent in more detailed cell planning

NNeeiigghhbboouurr cceellll rreellaattiioonnss

� The parameters to control the neighbour relations and the algorithms how system evaluates neighbours for cell lists, depend on vendor

� minimum CPICH RSCP or Ec/lo � Ec/lo margin � maximum number of neighbours

� A neighboring set (or monitored set) is defined for each cell � Utilise planning tools automatised functions and check

with drive tests � Optimise according to CPICI-l coverage and SHO

parameters � UE monitors the neighboring set that may contain

� Intra-frequency monitored list: Cells on the same WCDMA carrier (Soft HO)

� Inter-frequency neighbor list: Cells on another WCDMA carrier (hard HO)

� Inter-system neighbor list: For each neighboring PLMN � Missing neighbour can be detected during drive tests

� If the best cell shown in the 3G scanner does not enter the active set missing neighbour

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� Incilude the missing cell to neighbour list if it’s wanted to active set or change cell plan if FIO

SSHHOO ooppttiimmiissaattiioonn � Soft/Softer HO planning and correct operation is one of the

most important means of optimizing WCDMA networks � The importance is high because of the high biterate (pathloss

sensitive) and RT (delay sensitive) RABs

� SHO is measured in terms of probability, the percentage of all connections that are in SHO state

� The probability is effected by network planning and parameter settings

SSHHOO ooppttiimmiissaattiioonn � SHOs have effect to the network performance Advantages

� Required to avoid near-far effects � Coverage increases when more distant users can

connect � Capacity can be “increased” if more users can be

connected � Alongside with PC, SHO is the main interference

migitation means in WCDMA Inconvenient

� Requires more connections, thus eats DL transmission power and decreases capacity

� Introduces more interference to DL

� Increases the traffic in lub 40% SHO probability�1.4 times the traffic!

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SSHHOO ooppttiimmiissaattiioonn � Probability for soft HO should be set to 30-50% and for softer

HO to 5-15%, depending on the area � Too high SHO% results in excess overlapping between

cells —> other-cell interference increases —> capacity decreases

� Too high SHO% also leads to poorly utilised network capacity (unnecessary links)

� With too low SHO% the full potential of network is not utilised and transmission powers cannot be minimized —> trouble with interference

� SHO performance is planned with a planning tool and optimised by measurements in live network.

� In early stage SHO% can be planned high, since the traffic density is smaller. With increasing traffic coverage decreases and SHO areas become smaller.

� SHO% can be tuned with related parameters and dominance areas

� SHO most important in urban areas due to serious shadowing

SSuummmmaarryy KKPPII

Indicator KPI KPI target example Coverage Measured RSCP > -88 dBm over 97% of area

(value should be adapted based on required margins)

Interference Measured Ec/No > -9 dB over 95% of area Cell overlap Cell overlay < 3 cells over 95% of area

Cell Overshoot No cell detected above -111 dBm (CPICH RSCP)

Integrity of cell coverage

No cell fragmentation detected

Qualitative

Best server plot Clean boundary without un-necessary change of best server

- 15 -

QQuuaalliittyy ooff SSeerrvviiccee

- 16 -

QQuuaalliittyy ooff SSeerrvviiccee –– ddeeffiinniittiioonnss ((11)) QoS (ITU-T): << The collective effect of service performance which determines the degree of satisfaction of a user of the service>>. Network Performance, NP (ITU-T): << The ability of a network portion to provide the functions related to communication between users>>.

QQuuaalliittyy ooff SSeerrvviiccee –– ddeeffiinniittiioonnss ((22)) User domain: throughput, accuracy, dependability (reliability, availability), … Provider domain: delay, loss, utilisation, …

QQuuaalliittyy ooff SSeerrvviiccee––ddeeffiinniittiioonnss ((33)) QoS and NP, Performance network (ITU Rec. E800)

User QoS Requirements

QoS offered by Provider

QoS achieved by User

QoS experienced By Users

- 17 -

QQuuaalliittyy ooff SSeerrvviiccee aanndd uusseerr ssaattiissffaaccttiioonn

RRaaddiioo AAcccceessss BBeeaarreerr QQooSS

Commercial offer Competition Trends

User expectations in terms of QoS

Technical QoS Non-technical QoS

Network performance

Terminal performance

Sales points Customer care

Users satisfaction

- 18 -

RRaaddiioo AAcccceessss BBeeaarreerr � Main task of the UTRAN is to create and maintain RAB for

communication between UE and CN. � RAB is build up in order to give for CN elements an illusion

about fixed communication path to UE. � The network builds up the end-to-end QoS connection from

small pieces, which compose a complete chain without bottlenecks

� These pieces are called Bearers � When the connection is set up, the network elements negotiate

the QoS requirements of the bearers set up between them � The result is a compromise, in which the QoS requirements and

network’s capacity is taken into account.

UUMMTTSS QQooSS CCllaasssseess Traffic Class Example application

Conversation class Speech and video calls

Streaming class Real-time streaming video

Interactive class Web surfing

Background class File downloading, e-mails

UUMMTTSS QQooSS CCllaasssseess Traffic Class Properties

Conversation class Minimum fixed delay, no buffering, symmetric traffic, guaranteed bit rate

Streaming class Minimum variable delay, buffering allowed, asymmetric, guaranteed bit rate

Interactive class Moderate variable delay, buffering allowed, asymmetric traffic, no guaranteed bit rate

Background class Big variable delay, buffering allowed, asymmetric traffic, no guaranteed bit rate

- 19 -

UUMMTTSS QQooSS PPaarraammeetteerrss

Parameter Explanation

Maximum bit rate Defines the maximum bit rate when delivering information between end points of UMTS bearer (<2Mbps)

Guaranteed bit rate Defines the bit rate that the UMTS bearer must carry between its end points

Allowed transfer delay Set the limits for delay (>80ms)

QoS negotiable QoS of some services are not negotiable (speech), packet data services admit various QoS classes

SSoommee vvaalluueess ooff QQooSS UUMMTTSS ppaarraammeetteerrss ccllaasssseess

Traffic class Conversation Streaming Interactive Background Maximum throughput (kb/s)

<2048

Scheduling Yes/No Max. SDU size (octers)

<_ 1500 or 1502

Corrupted SDU delivery

Yes/No

Residual BER 5* 10-2, 10-2, 5* 10-3, 10-4,

10-6

5* 10-2, 10-2, 5* 10-3, 10-3,

10-4, 10-5, 10-6

4* 10-3, 10-5,

6* 10-8

4* 10-3, 10-5,

6* 10-8 SDU error rate 10-2, 7*10-3,

10-3 10-4, 10-5

10-1, 10-2, 7* 10-3, 10-3,

10-4, 10-5

10-3, 10-4, 10-6

10-3, 10-4, 10-6

Transfer delay (ms)

100 –maximum value

250 – maximum value

- 20 -

QQooSS NNeeggoottiiaattiioonn

QQooSS iinn UUMMTTSS

� In early UMTS Release 99 all conversational and streaming class traffic were offered over the CS bearer

� Voice � RT multimedia (e.g. videotelephony)

� In early Release 99 only Interactive and background class traffic utilisises the PS bearer

� Release 4 capable networks introduce some streaming class traffic on PS bearer as well

� Release 5 brings along a full portofolio of PS bearers also utilised for conversation traffic

E2E service request

Maximum bit rate Guaranteed bit rate Transfer delay QoS negotiable (y/n)

RRM: Admission control

Maximum bit rate Guaranteed bit rate Transfer delay QoS negotiable (y/n)

UMTS bearer service: Request for UMTS QoS Class

RAB assignment request

QoS negotiation

RAB assignment response

UMTS Bearer service with negotiated QoS

Radio bearer and radio link establishment

UE UTRA

(NB, RNC) CN

- 21 -

QQooSS iinn UUMMTTSS � The QoS over the air interface is implemented by matching

each radio bearer with a transport channel whose format set defines the QoS parameters

� The mapping is performed during the establishment of the RAB � RNC performs the mapping of RAB characteristics to actual

resource requirements (vendor dependent) � Example of mapping for web service, which belongs to the

interactive class

QQooSS iinn UUMMTTSS � Operators can define the wanted QoS profile (in HLR) per

subscriber � Users can be categorised (QoS differentiation) for various

tariffing schemes � Traffic handling priorities can be set (THP) Business Remote office Basic free time Traffic class All four allowed All four allowed Only

converational (voice calls) and background

Max bit rate 400 kbps 800 kbps 64 kbps Guaranteed bit rate

384 kbps 64 kbps 12 kbps

Allowed THPs THP 1 (e.g. for e-mail download)

THP 2 (e.g. for file tranfer)

THP 3

Maximum bit rate

Maximum SDU size

Residual BER

Transfers Delay

Guaranteed bit rate

Delivery order

SDU Error Ratio

Delivery of errorneous

Maximum bit rate

Maximum SDU size

Residual BER

Transfers Delay

Guaranteed bit rate

Delivery order

SDU Error Ratio

128 kbps

1500

10^ -6

NA

64 kbps

yes

1%

NO

SF=16

Map to Transport formats

1/3 turbo encoder

Interleaver=40 or 80 msec

SF=16

Use Acknowledged RLC

Set appropriate threshold for

Use Acknowledged RLC

Parameters Interactive Class Radio Resource mapping

- 22 -

QQooSS iinn UUMMTTSS

- 23 -

MMeeaassuurreemmeenntt aanndd ssttaattiissttiiccss ccoolllleeccttiioonn

- 24 -

MMeeaassuurreemmeenntt ttoooollss ttyyppoollooggyy

AA.. FFiieelldd mmeeaassuurreemmeennttss

DDrriivvee tteesstt eeqquuiippmmeenntt

PPoooorr CCoovveerraaggee eexxaammppllee

Measurement tools

Field Measurements

System Measurements

OMC counters

Passive capture tools

Calls generators

Generic

Specific

measures and

softwares

Controler

GPS

Energy

Mobile QoS test equipment

Processing

External antennas

Man to machine interface

- 25 -

PPoooorr CCeellll DDoommiinnaannccee eexxaammppllee

PPiilloott PPoolllluuttiioonn eexxaammppllee

- 26 -

EExxaammppllee ooff nneeiigghhbboorr mmiissssiinngg ((EEcc//IIoo))

CCoorrnneerr eeffffeecctt ((EEcc//IIoo))

- 27 -

QQVVOOIICCEE

BB.. SSyysstteemm mmeeaassuurreemmeennttss

OOMMCC mmeeaassuurreemmeennttss

PSTN / ISDN

Cellular Network

Post processing

Data collection

QVS

QVP-Server

QVP-Client

3 parts: QVM (QV Mobile), QVS (QV Stationary) et QVP (QV Post processing).

Specific • Alcatel: RNO • Siemens: SPOTS • Ericsson: TEMS Analyser • …

Generic • APIC from Metrica • MyCom from MYCom • AirCom • NetAct SQM: Nokia • OVPI: HP (for IP equipments)

- 28 -

KKPPII pprroocceessssiinngg ttoooollss

AAnnaallyyssiiss bbaasseedd oonn OOMMCC--RR ccoouunntteerrss Analysis tools using these counters (generally they are specific). Example: RNO or NPA of Alcatel, SPOTS from Siemens, etc.

• BiVision • ADC/Metrica, • NetAct (Nokia, for 3G)

• UTRAN Network and service Analyzer (Tektronix)

• Actix

Commercial tools:

- 29 -

PPaassssiivvee ttoooollss eexxaammpplleess • HP: Ovis (data services tests, producers KPIs). • RamCom: Network Consultant (A, Gb, Gi, Gn, Iub, Iur, Gi and

Gn interfaces) • Trafica (NetAct from Nokia) • Ipanema: Ipanema (2,5 G and 3G data traffic). • Cigale (Astellia): 2 and 3G traffic.

GGIISS ddiissppllaayy

- 30 -

KKPPII

- 31 -

OOppttiimmiizzaattiioonn pprroocceessss

NNeettwwoorrkk ssttaattiissttiiccss • Network statistics are collected from different network elements

with counters • Different types of counters are used • KPIs are needed to provide information of the network

performance • Raw counter data too detailed to be used in monitoring and

optimisation (Some counters can be used as KPIs)

KKPPII ddeeffiinniittiioonn • KPIs are composed from several counters • KPI categories

– Accessibility – Retainability – Integrity

• Documentation of KPIs is important – Same KPI can be defined from different counters or

formula can be incorrect • Measurement period must be reasonable

– Too much averaging if too long – Not enough statistical information if too short

Performance measurements

Performance analysis

Network tuning

Update of parameters, site

configuration

Key Performance Indicators (KPI)

• Reasons that lead to otimisation: – Improve the performance – Business reasons (cost-effective) – Troubleshooting

- 32 -

KKPPII EExxaammppllee Optimisation based on KIPs: • Optimisation is performed

for each category • Find the worst performing

cells • Find the reasons behind

the poor performance • Make the changes in the

network • Monitor the performance

after the changes

- 33 -

AAcccceessssiibbiilliittyy

- 34 -

AAcccceessssiibbiilliittyy :: ccaallll sseett--uupp

AAcccceessssiibbiilliittyy wwoorrkkffllooww

WWoorrsstt ppeerrffoorrmmiinngg cceellll ffoorr CCSS aanndd PPSS

RAB Assignment

Random Access

MS Originating Call Setup

RRC Connection Setup

Service Request Authentication

Security

Performance Measurements

Performance Analysis

Recommendation &

Implementation

Verification of changes

Other M

odules

pmTotNoRrcConnectCsSucc pmTotNoRrcConnectPsSucc pmNoRabEstablishAttempt<RAB> pmNoRabEstablishSuccess<RAB> pmNoPageDiscardCmpLoadC pmNoPagingAttemptUtranRejected

Idle mode RRC Connection Random Access NAS RAB Assignment

Squal, Srxlev, qQualmin, qRxLevMin, maxTxPowerUl, t3212, t3312, aichPower, powerOffsetP0, preambleRetransMax, constantValueCprach

Alarms Cell Availability Counters

� � �

� � � �

� > <

> < × � � �

� � � �

� ×

RAB Attempt bEstablish pmmTotNoRa RAB uccess EstablishS pmTotNoRab

Cs ConnectReq pmTotNoRrc CsSuccess ConnectReq pmTotNoRrc

100

� � �

� � � �

� > <

> < × � � �

� � � �

� × RAB Attempt bEstablish pmmTotNoRa

RAB uccess EstablishS pmTotNoRab Ps ConnectReq pmTotNoRrc

PsSuccess ConnectReq pmTotNoRrc 100

- 35 -

SSeerrvviiccee ssuucccceessss sseett uupp rraattee ((CCSS))

SSeerrvviiccee ssuucccceessss sseett uupp rraattee ((PPSS))

pmTotNoRrcConnectReqCsSucc pmTotNoRrcConnectReqCs

pmTotNoRabEstablishSuccessSpeech pmmTotNoRabEstablishAttemptSpeech x 100x

Speech

pmTotNoRrcConnectReqCsSucc pmTotNoRrcConnectReqCs

pmTotNoRabEstablishSuccessCS64 pmmTotNoRabEstablishAttemptCS64 x 100x

Circuit-Switched 64

Circuit-Switched 57

pmTotNoRrcConnectReqCsSucc pmTotNoRrcConnectReqCs

pmTotNoRabEstablishSuccessCS57 pmmTotNoRabEstablishAttemptCS57 x 100x

pmTotNoRabEstablishSuccessPacketStream + pmRabEstablishSuccessPacketStream128 pmTotNoRabEstablishAttemptPacketStream + pmRabEstablishAttemptPacketStream128 100 x (Y) x

pmTotNoRrcConnectReqPsSuccess PmTotNoRrcConnectReqPs Where Y =

Packet-Switched Data Streaming

Packet-Switched Data Interactive

pmTotNoRabEstablishSuccessInteractive pmTotNoRabEstablishAttemptPacketInteractive + HS1_HardHO_Flow 100 x (Y) x

pmTotNoRrcConnectReqPsSuccess pmTotNoRrcConnectReqPs Y x

Where

HS1_HardHO_Flow= pmNoOutgoingHsHardHoAttempt – pmNoHsHardHoReturnOidSource -pmNoIncomingHsHardHoAttempt - pmNoHsHardHoReturnOldChTarget

- 36 -

IIddllee mmooddee ppaaggiinngg

RRaannddoomm aacccceessss:: pprreeaammbbllee ddeetteeccttiioonn Number/percentage of false detections, which is the case that preamble is detected but there is no enough energy in message part, due to noise on the random access channel for a carrier (it could be due to loss of AICH, wrong recognition of preamble or loss of RACH message part after the UE sends message out):

RRaannddoomm aacccceessss:: AAIICCHH ddeetteeccttiioonn Percentage of getting AICH but no RRC connection setup, excluding cell (re)selection:

Successful First and Repeated Page attempts of total number of first attempts, Paging success rate in aMSC

NPAAG1RESUCC + NPAG2RESUCC NPAG1GLTOT + NPAG1LOTOT

100 x

Paging intensity per cell in a RNC (if RNC, LA and RA consist of exact same cells):

pmCnlnitPagingToldleUeLa + pmCninitPagingToldieUeRa + pmCnlnitPagingToldleUe Measurement period x total number of cells in that RNC

pmNoPreambleFalseDetection or

x100% pmNoPreambleFalseDetection pmPositiveMessages

x100% No of AICH_ACK-No of RRC connection setup-No of cell (re)selection during RRC establishment No of AICH_ACK

- 37 -

AAddmmiissssiioonn ccoonnttrrooll:: DDLL ttrraannssmmiissssiioonn ccaarrrriieerr ppoowweerr

AAddmmiissssiioonn ccoonnttrrooll:: UULL RRSSSSII

AAddmmiissssiioonn ccoonnttrrooll:: AAiirr IInntteerrffaaccee SSppeeeecchh EEqquuiivvaalleenntt ((AASSEE))

pmTransmittedCarrierPoweri x

pmTransmittedCarrierPoweri

i 2 �

102

�=0

� 102

�=0

Average DL TX power for a cell-carrier:

DL transmission carrier power

[pmAverageRssii x (0.5xi – 110.5)]

pmAverageRssii

� 62

�=0

� 62

�=0

Average UL RSSI for a cell-carrier:

Average UL ASE for a cell: pmSumOfSampleAseUI

pmNoOfSampleAseUI

Average DL ASE for a cell: pmSumOfSampleAseDI

pmNoOfSampleAseDI

- 38 -

AAddmmiissssiioonn ccoonnttrrooll:: ccooddee aallllooccaattiioonn Code allocation failure for SFn, where n is the spreading factor for a cell could be found in the following formula (as an example the SF 128 was used):

AAddmmiissssiioonn ccoonnttrrooll:: ccoommpprreesssseedd mmooddee How many users are in compressed mode? Well the average number of users in compressed mode for a cell:

AAddmmiissssiioonn ccoonnttrrooll:: llooaadd sshhaarriinngg

pmNoDIChCodeAllocFailureSF128

pmNoDIChCodeAllocAttemptSF128 x100%

pmSumCompMode

pmSampesCompMode

Ratio between RRc connection returning and redirection due to load sharing for a cell:

pmNoDirRetrySuccess

pmNoDirectionRetryAtt x100%

The failures can be observed by the successful rate of directed retry to GSM for a cell:

pmNoOfReturingRrcConn

pmNoLoadSharingRrcConn

- 39 -

RReettaaiinnaabbiilliittyy

- 40 -

SSeerrvviiccee rreettaaiinnaabbiilliittyy wwoorrkkffllooww

DDrrooppppeedd ccaallll rraattee CCSS

DDrrooppppeedd ccaallll rraattee PPSS

Performance Measurements

Performance Analysis

Recommendation &

Implementation

Verification of changes

Other M

odules

pmSystemRabRelease<RAB> pmNormalRabRelease<RAB> pmNoSysRelSpeechULSynch pmNoOfTermSpeechCong pmNoSysRelSpeechSoHo

UL out of Synch Congestion control, SHO functions IFHO functions IRAT Handovers

ReleaseConnOffset maxTxPowerUl,SirMax, MinPwrRl, treselection, timetotrigger1, reportingrange1

pmNoSystemRab ReleaseSpeech

(pmNoNormalrAB ReleaseSpeech + pmNoSystemRab ReleaseSpeech)

pmNoSystemRabReleaseCs64

(pmNoNormalRab ReleaseCs64 + pmNoSystemRab ReleaseCs64)

pmNoSystemRabReleaseCsStream

(pmNoNormalrRab ReleaseCsStream + pmNoSystemRab ReleaseCsStream)

Speech

Circuit-switched Streaming

Circuit-switched 64

100x

100x

100x

Packet Switched data Streaming

pmNoSystemRabReleasePacketStream + pmNoSystemRabReleasePacketStream128 (pmNoNormalRabReleasePacketStream + pmNoSystemRabReleasePacketStream + pmNosystemRabReleasePacketStream128)

100x

pmNoSystemRabReleasePacket (pmNoNormalRabReleasePacket + pmNoSystemRabReleasePacket) 100x

Packet Switched data Interactive

- 41 -

MMiinnuutteess ppeerr ddrroopp CCSS

MMiinnuutteess ppeerr ddrroopp PPSS

HHaannddoovveerr ffaaiilluurree rraattee The following formula shows the failure rate for RL addition/replacement to active set

Sp_U_User

pmNoSystemRabReleaseSpeech 100x x number of minutes

Cs64_U_User

pmNoSystemRabReleaseCs64 100x x number of minutes

Cs57_U_User

pmNoSystemRabReleaseCsStream 100x x number of minutes

Circuit-switched Streaming

Circuit-switched 64

Speech

Pstr_P8_U_User

pmNoSyatemRab ReleasePacketStream + pmNoSystemRab ReleasePacketStream128 100 x No of minutes

Plntdch_U_User+PlntHs_U_User+PlntFach_U_User

pmNoSystemRab ReleasePacket 100 x No of minutes

PlntHs_U_User

pmNoSystemRab ReleaseHs 100 x No of minutes

Packet Switched data Streaming

Packet Switched data Interactive

Packet Switched data Interactive HS

pmNoTimesCellFailAddToActSet

(pmNoTimesCellFailAddToAct + pmNoTimesRlAddToActSet 100x

- 42 -

HHaannddoovveerr ffaaiilluurree rraattee:: HHSS cceellll cchhaannggee The following metric measures the success rate for HS Cell Change in target cell

HHaannddoovveerr ffaaiilluurree rraattee:: oouutt ooff ssyynncchhrroonniizzaattiioonn Shows fraction of drop due to uplink Out of Sync reason.

HHaannddoovveerr ffaaiilluurree rraattee:: mmiissssiinngg nneeiigghhbboorr

100x

(pmNoSysRelSpeechULSynch)

(pmNoNormalRabReleaseSpeech + pmNoSystemRabReleaseSpeech) 100x

pmNoSysRelSpeechSoHo

(pmNoSystemRabReleaseSpeech + pmNoNormalRabReleaseSpeech) 100x

pmNoSysRelSpeechNeighbr

(pmNoSystemRabReleaseSpeech + pmNoNormalRabReleaseSpeech) 100x

Shows fraction of speech drop due to missing neighbour reason when a non-valid cell cannot ne added to active set.

Shows fraction of speech drop due to HO action when a valid or non-valid cell cannot be added to active set. This includes also drop due to missing neighbour.

pmHsCcSuccess

pmHsCcAttempt

- 43 -

IInntteerr--ffrreeqquueennccyy hhaannddoovveerr ffaaiilluurree rraattee ((CCSS)) Drop due to IHO failure for speech: Outgoing IFHO failure when UE failed to return to present active set.

IInntteerr--ffrreeqquueennccyy hhaannddoovveerr ffaaiilluurree rraattee ((PPSS))

pmFailNonBlindInterFreqHoFailRevertCsSpeech12

pmAttNonBlindInterFreqHoCsSpeech12 100x

Drop due to IFHO failure for PS less or equal to 64 kbps: Outgoing IFHO failure when UE failed to return to present active set.

Drop due to IFHO failure for PS streaming and others: Outgoing IFHO failure when UE failed to return to present active set.

pmFailNonBlindInterFreqHoFailRevertPsInteractiveLess64

pmAttNonBlindInterFreqHoPsInteractiveLess64 100x

pmFailNonBlindInterFreqHoFailRevertPsInteractiveGreater64

pmAttNonBlindInterFreqHoPsInteractiveGreater64 100x

pmFailNonBlindInterFreqHoFailRevertStreamingOther

pmAttNonBlindInterFreqHoStreamingOther 100x

Drop due to IFHO failure for PS greater than 64 kbps: Outgoing IFHO failure when UE failed to return to present active set.

- 44 -

IIRRAATT hhaannddoovveerr

IIRRAATT hhaannddoovveerr

CCoonnggeessttiioonn

pmNoSuccessOutIratHoSpeech

pmNoAttOutIratHoSpeech 100x

The following metric measures hard handover success rate between UtranCell and target GSM cell for speech calls. The formula is considering the GsmRelation.

pmNoSuccessOutIratHoCs57

pmNoAttOutIratHoCs57 100x

The following metric measures hard handover success rate between UtranCell and target GSM cell for streaming calls. The formula is considering the GsmRelation.

pmNoSuccessOutIratHoMulti

pmNoAttOutIratHoMulti 100x

The following metric measures hard handover success rate between UtranCell and target GSM cell for Multi-RAB calls. The formula is considering the GsmRelation.

pmNoOutIratCcReturnOldCh

pmNoOutIratCcAtt 100x

The following metric measures cell change failure rate between UtranCell and target GSM cell for PS calls when the UE successfully returns to UtranCell. The formula is considering the GsmRelation.

(pmNoOfTermSpeechCong)

(pmNoNormalRabReleaseSpeech + pmNoSystemRabReleaseSpeech) 100x

(pmNoOfTermSpeechCong)

(pmNoNormalRabReleaseCs64 + pmNoSystemRabReleaseCs64) 100x

Shows fraction of video call drop due to cogestion action

Shows fraction of speech drop due to cogestion action

- 45 -

IInntteeggrriittyy

- 46 -

SSeerrvviiccee iinntteeggrriittyy wwoorrkkffllooww

BBLLEERR The method for finding worst performing cells is based on top to down analysis. Initial worst 10-15 performing cells can be identified based on the Uplink Block Error rate before combining.

TThhrroouugghhppuutt

Performance Measurements

Performance Analysis

Recommendation &

Implementation

Verification of changes

pmFaultyTransportBlocksBcUl pmTransportBlocksBcUl pmNoOfSwDownNgCong PmNoOfSwDownNgAdm PmDl Traffic volume counters

BLER, power, SIR parameters Throughput

Test the settings Check statistics If not OK, roll back

BLER counters and Down Switching counters

100x

pmDlTrafficVolume<RAB> pmSum<RAB>RabEstablish

pmSamples<RAB>RabEstablish *ROPsec

Throughput =

Average throughput per cell and RAB in the DL, excluding HSDPA:

Actual Bitrate per RAB

Nominal Bitrate per UeRc=x RABEfficiency =

The RAB efficiency can also be checked

RAB efficiency excluding HSDPA

UeRc stands for different RAB’s UeRc=2, Speech UeRc=3, Video Call UeRc=4, Packet Common Channel UeRc=5, PS 64/64 UeRc=6, PS64/128 UeRc=7, PS 64/384 UeRc=10 multirab Speech+PS 0 or PS 64/64).

pmFaultyTranspoertBlocksBcUL

pmTransportBlocksBcUI

- 47 -

PPaayyllooaadd ccoouunntteerrss

Radio Connection

type

UL Payload counter DL Payload counter

Speech pmUITrafficVolumeCs12 pmUITrafficVolumeCs12 PS64/64 pmUITrafficVolumePs64 pmUITrafficVolumePs64 PS64/128 pmUITrafficVolumePs128 pmUITrafficVolumePs128 PS64/384 pmUITrafficVolumePs384 pmUITrafficVolumePs384 CS 57.6

(streaming) pmUITrafficVolumeCs57 pmUITrafficVolumeCs57

CS 64 (UDI) pmUITrafficVolumeCs57 pmUITrafficVolumeCs57 Speech/PS 64 multirab

pmUITrafficVolumeCs12Ps64 pmUITrafficVolumeCs12Ps64

PS Common

pmUITrafficVolumePsCommon pmUITrafficVolumePsCommon

- 48 -

HHSSDDPPAA--HHSSUUPPAA

- 49 -

HHSSPPAA KKeeyy ffeeaattuurreess--AAMMCC

HHSSPPAA KKeeyy ffeeaattuurree –– SSyysstteemm rreessoouurrccee

AMC could improve radio bandwidth and fit for high speed radio transmission.

Cood CQI

Bad CQI

High Code Effective Rate

Low Code Effective Rate

Good coverage Bad coverage

Channel Quality Feedback (CQI) UE measures channel quality (SNR or Ec/No) and reports to Node B every 2ms or longer time. Node B chooses modulation scheme, transport block size and code effective rate based on CQI

DCH Code For R99 and HSPA access and traffic channel

HSPA Maximum Code

HSPA Minimum Code

OVSF Code resource

Minimum Code available for HSPA but not for R99, so this resource can’t allocated too much to avoid no code for HSPA access channel.

Reasonable resource allocation can improve throughput performance

Resource allocation

Power resource Threshold for R99 load control, which should not be allocated too much to avoid no power for HSPA user

- 50 -

HHSSPPAA KKeeyy ffeeaattuurree--SScchheedduulliinngg

MMoobbiilliittyy mmaannaaggeemmeenntt

Transmission slot 2 ms

Data transmission slot

UE1

UE2 UE3

- 51 -

SSaammppllee mmeessssaaggee ffllooww ttoo bbeeggiinn HHSSDDPPAA ooppeerraattiioonn

SSaammppllee mmeessssaaggee ffllooww ttoo ssttoopp HHSSDDPPAA ooppeerraattiioonn

UE Bode B RNC

UTRAN decides to start HSDPA for the UE

User plan data can flow on the HS-DSCH

Measurement Control message (Setup Event 1d)

Measurement Report message (Report Event 1d)

Radio link reconfiguration prepare

Radio link reconfiguration ready

Radio link reconfiguration commit

Radio Bearer Reconfiguration message

Radio Bearer Reconfiguration Complete message

1

2

3

4

UE Bode B RNC

UTRAN decides to stop HSDPA but keep DCH for the UE due to: • Low Downlink data activity • High UE mobility

User plane data only flows on the DCH

Radio link reconfiguration prepare

Radio link reconfiguration ready

Radio link reconfiguration commit

Radio Bearer Reconfiguration message

Radio Bearer Reconfiguration message

1

2

3

- 52 -

CCeellll cchhaannggee ttrriiggggeerriinngg wwiitthh eevveenntt 11dd

DDiiffffeerreenncceess aabboouutt iinnffoorrmmaattiioonn ccoolllleeccttiioonn bbeettwweeeenn RR9999 aanndd HHSSPPAA

Time-to- Cell change

HS-DSCH on Cell 1 HS-DSCH on

Cell 2

Cell 1 Ec/No

A B C

Hysteresis

Time

- 53 -

HHSSPPAA ddiimmeennssiioonniinngg ooppttiimmiizzaattiioonn

HHSSPPAA OOppttiimmiizzaattiioonn ttaarrggeett –– IImmpprroovvee CCQQII

� -9dB -15 dB - -9dB � -15dB Equipment Ec/Io

Good Fair Poor User experience

CQI�15 15>CQI�9 9>CQI CDI

Make sure that CQI is distributed as appropriate proportion. Cell edge throughput requirement could be fulfilled in the door coverage area.

CQI

HSPA RF optimization target R99 RF optimization target

RSCP & Ec/Io

Make sure that cell gets target coverage probability

- 54 -

PPeerrffoorrmmaannccee OOppttiimmiizzaattiioonn PPrroocceedduurree

IInntteerr--ffrreeqq HHaannddoovveerr iiss tthhee mmoosstt ddiiffffiiccuulltt ffoorr HHSSPPAA mmoobbiilliittyy ooppttiimmiizzaattiioonn

Problem Analyze • Code congestion • Power overload • HSPA subscriber number overload • lub bandwidth congestion • Unsupported configuration by UE

KPI Collection DT/CQT/Statistics

Performance optimization • Modify the load balance policy • Carry out smart admission algorithm such as DRD or Downsize Access • Power and lub bandwidth congestion means the capacity should be expanded • The higher bit rate such as 13.6K DCH channel can help to improve access performance

The three kind of KPI of should be paid more attention HSPA CALL SUCCESS RATIO HSPA HANDOVER SUCCESS RATIO HSPA THROUGHPUT PERFORMANCE

- 55 -

HHSSPPAA TThhrroouugghhppuutt OOppttiimmiizzaattiioonn

The Power and Codes available for HS-PDSCH, the lub bandwidth and RF environment of UE position will all impact throughput user got.

DATA

DATA

DATA

DATA

CQI

CQI

CQI

CQI

The air environment

condition

The web sever performance.

GSN Process ability

The data should be delivered

Available lub backhaul for HSPA The Data Power to be transmitted

Available Codes for HSPA Available Power for HSPA

App Sever

Node B

Firewall

SGSN/GGSN

RNC

Check point

- 56 -