3G RF Opt Process

Soc Classification level 1 © Nokia Siemens Networks Presentation / Author / Date

3G RF optimisation

Regional planning team (VF south)


RF Optimisation - Introduction

Make RF Scanning & Verification to look at:

Dominance

DL coverage

Quality

Pilot Pollution

UL Coverage

Make Neighbour list Verification

RAN KPI / Performance Analysis

Make RF Optimisation to:

•Improve coverage areas and sharpen dominance areas

•Optimise SHO area

•Eliminate Pilot Pollution


RF Feild Optimisation

•For RF Optimisation and neighbour verification both Scanner and UE measurements are required simultaneously

•Post-Processing tool is required for data analysis

• Individual call failures or drops can be analysed with Drive test tools (e.g. Nemo Outdoor) but to get bigger picture, a proper analysis tool is required

• Actix or Nemo Analyser can be used for

– Data analysis

– Create Maps

– Create KPI reports


RF scannerThe purpose of using the RF scanner is to be able to scan and measure all used carriers/cells and their corresponding DL scrambling codes. This gives the full picture of the (on air) radio network within a selected frequency band. The results are used to identify and understand reasons for peculiar behaviour discovered during field measurements. In addition, the scanner will indicate presence of “illegal” RF interference within the sub bands allocated to the network. The scanner data analyses can be done for many purposes:-

For low coverage areas

For antenna installation problems

For missing neighbours

For coverage optimisation

With the scanner you can get the following info from the surrounding cells:

Different Scrambling codes

CPCIH RSCP value (dBm)

CPICH EcNo value (dB)

UE measurements are different than to RF scanner measurements. The Scanner measures all SCs, whereas the UE only measures SC signals from the cells that the system has informed/ordered the UE through the BCH (neighbour list) or via the “measurement control” message. With this we can get following info:

The BLER downlinkCarrier RSSIData Throughput DownlinkData Throughput UplinkEc/No Active CellEc/No Monitored CellPilot BERRandom Access Initial Tx PowerRandom Access Preamble CountRandom Access Preamble StepRandom Access Tx PowerSIR targetUE Tx Power Call Statistic: AMR, CS and PS data calls


Radio Link Performance Troubleshooting:

Distant servers Too many servers Unnecessarily large neighbour lists Excessive soft handoff

Event Detection and Drive Test Analysis:

Coverage problems Poor UL or DL, coverage limited, interference Handover problems Missing neighbours Pilot pollution

Overall Call View: Detailed dropped call and failed set-up level analysis Detected problem(s) identified per call Individual call extraction for detailed message level analysis

Neighbour List Analysis:

Generation of recommendations for optimal neighbour list settings Integration with Network Element Database Based on UMTS/WCDMA scanner drive test data

Supported Measurements with Scanner are:

Layer 1 scanner measurements (for example EcIo, RSCP, etc.)

Supported Measurements with Handset are:

Layer 1 handset measurements (for example EcNo, TxPow, etc.) RRC Layer 3 signalling – Call Control (CC), Mobility Management (MM), GPRS Mobility Management,

GPRS Session Management

Actix :Analysis tool Actix analyser is a tool for post-processing cellular network data (GSM, CDMA, WCDMA). The tool is specifically tailored to import measurement data from various (measurement) tools and file formats and then present it in map, table, workbook or chart format. Also it is possible to define your own specific queries

Below is a list of the capabilities of Analyser:-


Dominance Verification

First task is to overlay the cells dominance area to check that the coverage areas of the cells are clear, all sites are “on air” and there are no cross feeders

Missing Site- No dominance

server in the area


Coverage

•If lack of coverage is indicated then coverage enhancement is required.

•Has excessive tilting been used? Is up-tilting or an Panning the antenna an option for some cells.

•For initial roll out stages (low traffic) increasing the P-CPICH power is an option the feasibility will depend upon the margins in the link budget

•

Poor coverage during Pre- Optimisation & Acceptance

due the missing site


Coverage

Planned Site

Planned Site

Planned Site

Planned Site

•What impact will any planned sites (if any) have on the overall performance?

• A study of UE logs for the area should provide an indication of the number of failed Setups/calls that would have been prevented if a planned site was available.

•Failures due to missing sites needs to be estimated and this information should be communicated to the operator. It may be possible to influence the roll out schedule based on this information


Coverage verification with RSCP Scan for each SC

•CPICH_SCAN_RSCP_for SC X overlay plotted out for all three sectors of a site showing the coverage for each sector

•Gives a good indication if a sector is radiating too far and may need down tilt.

281

282

280

Scan RSCP for SC 282 Scan RSCP for SC 280 Scan RSCP for SC 281

280 281

Note !!


Sector C-SC162

SC162

No measurements in vicinity of sector C (SC = 162)

Sector B-SC161

No measurements in vicinity of sector C (SC = 162)

Verification of Swapped feeder or other issue

•Plotting RSCP of each SC highlights any hardware or databuild issues where the coverage area of the cell is different to the planned coverage.

•This will include swapped feeders, incorrect azimuths/tilts or incorrect scrambling codes assigned to the cell

SC161 and SC162 Tx from same

sectorcrossed feeders can occur at:

• Antenna

• Input to BTS

• Within the BTS


RSCP Verification

Check that the RSCP levels for the area meet the target thresholds for the service and environment (clutter, building loss)


Ec/No Quality

•Identify areas of poor quality

•Identify excessive polluters (overshooting cells)

•Recommend physical optimisation: downtilts and panning.

•Implement changes.

•Success criteria: improved quality, no reduction in coverage


Ec/No Verification

If coverage is acceptable then check for area of poor EcNo in the area.

Poor coverage areas can still have good Ec/No if

there is dominating server


Pilot Pollution Analysis I

Pilot pollution areas can be shown with Scanner Pilot Pollution query with user defined RSCP and EcNo levels

(CPICH_SCAN_EcNo_Sorted_By_EcNo (0)<-12) AND (CPICH_SCAN_RSCP_Sorted_By_EcNo (0)>-92)


Pilot Pollution Analysis II

Pilot polluter workbook shows the worst polluters in the area e.g. SC 344 have most of the samples

SC 344 displayed over pilot pollution


Pilot Pollution Example

Scanner sees 5 SC’s, all within 5 dB

of each other.

This is clearly an area suffering from

pilot pollution.

RSCP is good -91 dBm but EcNo is bad

-10 dB

Looking at the dashed lines to the cells serving at this

point we can see that there are several cells (SCs 136,

496, 272) which are not particularly close to the point

in question and are candidates for down-tilting


Pilot Pollution Example

SC 272

• This site is clearly radiating much too far and is a definite candidate for down-tilting.

• By removing scrambling codes within 5dBs of the best server, we can improve the best server’s Ec/Io

SC 272 is the furthest away these sites and is joint second best server.


UL Coverage Verification

By using UE together with Scanner during testing we can check the UEs transmit power for problem areas where UE cannot maintain the link quality


Multi-pathProblem

A

Dominance Area OK

Yes

amount of ScramblingCodes > X

A

No

A

No

LowCPICH Ec

Pilot Pollution

Aggregated to Peak> 3 dB

A

Yes

A

BadEc/Io

No

A Possible Actions/Solutions

1. Antenna Tilting 2. Antenna Panning3. Change Antenna Type4. Change Antenna Height 5. Change CPICH Tx Pwr6. (Add sites)

Scanner and UE drive logs

Compare scanner measurements with planned quality and coverage

thresholds

CPICH RSCP => planned threshold

e.g. -90 dBm

CPICH Ec/No => planned threshold e.g. -12 dBm

Yes

Yes

Yes

No

No

Coverage target agreed with customer

Ec/No target agreed with customer & depends service mix

Currently X = Max AS size = 3 for Nokia RAN

Drive test data analysis


RF Optimisation

• Check if the cause of call setup failure is CPICH RSCP and Ec/No coverage problem

• The received best server’s CPICH RSCP and Ec/No will be compared to the coverage thresholds at the location where call setup failed and if best server’s CPICH RSCP OR Ec/No is less than the thresholds, coverage optimisation will be performed.

• The thresholds of CPICH RSCP and Ec/No depend on UE’s sensitivity:– CPICH RSCP coverage threshold = -110 dBm

– CPICH Ec/No coverage threshold = -16 dB

•Simulation using NetActPlanner will be used to verify the proposed coverage optimisation solution e.g. Antenna tilting or Panning


KPI Route CSF Causes

8.33%

8.33% 8.33%

75.00%

RF Issue : Interference

System Issue :NodeB

UE Issue

Unknown

KPI Route Call Drop Causes

11.11%

14.81%18.52%

29.63%

3.70%22.22% RF Issue : Interference

AS Update Failure :

Cause unknown

Unknown

UE Issue

Missing neighbor

RF Issue : Coverage

To better understand the failure mechanisms that contribute to radio failure as measured with network statistics.

Categorise the failure causes for Call Setup and drop call performance.

• Drop Call analysis shows that significant proportion of Interference failures is due the missing neighbour

• Analysis also confirms that conclusion derived from the scanner data that DL interference is major contributing factor to failure on the radio Interface

UE Measurements


Down-tilting of interfering cells’ antenna, which generate pilot pollution

Change CPICH Tx Power: Increase serving cell’s Tx power but decrease interfering cell’s Tx power

Change antenna bearing angles of cells involved in pilot pollution

Change antenna patterns of cells involved in pilot pollution. Smaller gains for interfering cells and higher gain for victim cell

Decrease antenna height of interfering cells and increase antenna height of victim cell with adequate tilting angle

Reducing the tilt of serving cell’s antenna to extend coverage radius and to improve unsatisfied coverage area

Increase CPICH Tx Power of serving cell

Change Antenna Bearing Angle: Focus the main beam of antenna to coverage holes and low RSCP area

Change Antenna Pattern: Displace with higher gain antenna with adequate antenna tilting

Increase serving cell’s antenna height to get higher effective antenna gain but there is risk to make undesirable inter-cell interference to adjacent cells

Tuning methods for Coverage Problem Area

Tuning methods for Dominance Problem AreaHigh PriorityHigh Priority

RF Optimisation


Physical Optimisation - Antenna changes

Antenna tilting (or panning) is needed mainly if:

• There is too much interference created by a site covering too much (overshooting)

• There is lack of coverage or dominance

One should carefully consider the tilt type

• Electrical or mechanical (both have advantages and disadvantages)

Antenna tilting should be followed by another round of drive-tests in order to evaluate the impact

Multiple antenna tilt or azimuth changes in the same time in the same area should be avoided

Decisions must be made based on scanner measurements.

• UE measurements can be also used, but they can sometimes lead to wrong results, for example in case of missing neighbours.

Tilt changes include both down and up-tilting.


Mechanical

• The downtilt angle varies over the horizontal beamwidth. Patterns measured ±90° from the centre of the beam have decreasing tilt angle until there is no tilt 90° from the main beam.

• The horizontal half-power beam width increases with greater downtilt angle.

• The resulting gain reduction depends on azimuth direction.

Electrical

• There is uniform downtilt over the whole azimuth range.

• The horizontal half-power beamwidth is independent of the downtilt angle.

• There is identical gain reduction in all azimuth directions. from Kathrein, Scala Division

Electrical vs. Mechanical Tilting


Mechanical Tilt require Site Visit

No “real“ maximum tilt angle

Mechanical down tilt causes deformation in the horizontal pattern

Deformation of the horizontal pattern

Mechanical Down tilt kit

Mechanical Tilt


Electrical Tilt

•The Adjustable EDT antennas can be adjusted manually or remotely

•Phase shifters provides variable phase distribution which in turn keeps the pattern shape constant

•Maximum Adjustable EDT range approx. 0-14° (normally 0-8°)

•For a higher downtilt angle a combination of the Mechanical DT and the Adjustable EDT is recommended

Horizontal pattern remains constant

Remote use

Manual use


Impact on Ec/NoImpact on Ec/No

Antenna tilt example (6 degrees downtilt)


Impact on Ec/NoImpact on Ec/No

Antenna tilt example (4 degrees downtilt)


Antenna tilt example -1 deg E-tilt – Overshooting Cell

No dominant Server in the area due the missing

site JS9218

Site JS9125 (SC28) from cluster 5 is overshooting to cluster 1

Before After

Site JS9125 (SC28) was tilted by 1 deg (E-tilt From 4 deg to 5 deg)


Neighbour List Verification

Neighbour definitions required by cell re-selection and handover

Soft handovers are based upon intra-frequency neighbour list

Hard handovers are based upon either intra-frequency (Between RNCs without Iur or Iur congestion) , inter-frequency (IFHO) or inter-system (ISHO) neighbour lists

Each neighbour has a set of associated parameters e.g. CPICH measurement offset

The post processing tool should be able to suggest appropriate neighbour lists

Strategy for initial system deployment is to place the emphasis upon adding neighbours rather than removing them

Inter-Frequenc

y Neighbors

Cell kCell lCell mCell nCell o

Max. 4

8(3

2

/carrie

r)

Inter-System Neighbo

rsCell rCell sCell tCell uCell v

Max.

32

Total max 111 in RNC database, limitation due to specifications of SIB11/12

size


There is a restriction on the number of cells contained in SIB 11/12 due to an inconsistency problem in the standards

SIB 11/12 should be able to contain a maximum of 96 neighbours

• (32 intra-frequency cells, 32 inter-frequency cells and 32 GSM cells)

On the other hand, the physical size of SIB data (no more than 3552 bits) has capacity only for about (depending on the type etc.) 47 cells!!

If too many adjacencies are declared, the cell will go blocked by system with alarm:

• 7771 WCDMA CELL OUT OF USE (BCCH scheduling error)

As a rule of thumb, assuming that …

ADJS=15, ADJG=15, ADJI=15

… and “realistic worst case values”, SIB11 length = 3187.5 < 3552 -> OK!! Some sites might need additional neighbors and might pose a problem with the SIB11 limitation• Avoid setting AdjsQoffset2 values, different CPICH values or other parameters

used to tune cell reselection or handover

Further information Technical Note No. 046 / Restriction on number of cells in SIB11/12 due to inconsistency problem in 3GPP TS 25.331

Max. 96 neighbours due SIB limitation

Neighbour List Verification – SIB 11/12


Neighbour List Verification – SIB 11/12

When offsets are added to the neighbours or the CPICH power of the neighbour cell is different to that of the serving cell the length of the message for each neighbour in SIB 11/12 is increased

• The length of one ADJS with no offsets is 48 bits

• The length of an ADJS with AdjsQoffset1 or AdjsQoffset2 is 48 or 56 bits on a case by case basis (average length 55.2 bits)

• The length of an ADJS with AdjsQoffset1 and AdjsQoffset2 is 56 or 64 bits on a case by case basis (average length 62.1 bits)

When the neighbour cell has a different CPICH Tx Power from the serving cell

• Without Offset and AdjsPtxCPICH : 54.2bits

• With AdjsQOffset1 or AdjsQOffset2 : 61.1bits

• With both AdjsQOffset1 and AdjsQOffset2 : 68bits



There are a number of approaches that can be used to both plan and verify the neighbour plan

Drive Testing

Neighbour Creation Manual Check Analytical

Planning Tool

Other

Neighbour Creation

Neighbour Verification

Manual Check

Measured

Network Stats


Neighbour List Verification - Analytical

•Analytical Neighbour Planning methods are traditionally used to generate original neighbour lists but they can also be used for verification and new site addition.

•Planning Tools – use coverage arrays and handover parameter data to determine required neighbour relations

•Other desk top tools can be based on:

• Site coordinate data,

• Cell azimuth data,

• Cell coverage distance estimations

• Antenna beam widths


Neighbour List Verification - Manual

• Cell in blue had nine 3G neighbours defined – highlighted in green on map

• 6 missing neighbours were identified for this site and added – Manual Check would have identified at least 5


• Process starts directly with the drive test

Record drive test results with Scanner in

‘TOP N’ mode

Start

Neighbour List Verification – Drive Test

Input Data Source

CPICH Scrambling code Ec/Io Scanner

Measurement position Scanner

Cell ID, cell position, cell azimuth Planning Tool

Cell scrambling code Radio Design

Cell neighbour list Planning Tool


High Level Process Record drive test

results with Scanner in ‘TOP N’ mode

Analysis (within Actix Analyzer)

Start

Finish

Numerical Analysis

• Part automatic and part manual neighbour list analysis• Analysis within a tool such as Actix Analyzer is automatic and numerical• Analysis requires the definition of a neighbour window which is applied to the

CPICH Ec/Io measurements• Recommended to set the neighbour window as 10 dB (drop window + margin)

Neighbour Window

Ec/Io

Time

Strongest Ec/Io

Neighbours reported when

within this range

21634983436

SC Site Sector

97 85 (47.4%); 303 (17.5%)

Num Of Samples Suggested NBR Additions

Reading Rubgy FC 00179719B2 97 351 (28.9%)Ewer Park Stud 00161126C

WOODLEY ATE 00001085A 96 350 (34.4%); 84 (25.0%)TILEHURST ATE 00001081B 90 434 (22.2%); 283 (22.2%)



• Analysis provided by the post processing tool:

• Consider adding neighbours reported by the tool

• If neighbour list is full then consider replacing some of the existing neighbours

• Do not remove existing neighbours without further investigation

Run (Actix) Analyzer Routine

Run (Actix) Analyzer Routine

NoConsider adding Consider adding suggested suggested neighboursneighbours

Consider adding Consider adding suggested suggested neighboursneighbours

Start

Progress to further additions

Is the Neighbour List full?

Is the Neighbour List full?

Consider Consider replacing replacing existing existing

neighbours by neighbours by those suggested those suggested

by the toolby the tool

Consider Consider replacing replacing existing existing

neighbours by neighbours by those suggested those suggested

by the toolby the tool



• As a minimum define the neighbour list as

All cells belonging to that siteThe first perimeter of cells

Cell for which the neighbour list is being defined

Neighbours

Yes

Add neighbours

Add neighbours

Complete visual inspection of neighbour list

Complete visual inspection of neighbour list

Does list include all cells belonging

to that site and the first perimeter

of cells

Does list include all cells belonging

to that site and the first perimeter

of cells

Continue from Analysis

Finish

Add any other neighbours which

may improve coverage

Add any other neighbours which

may improve coverage

• Subsequent manual tuning of neighbour list


NO

Soc Classification level 40 © Nokia Siemens Networks

Optimisation activities to improve call performance

Presentation / Author / Date

Common performance issues that affect any serviceVoice (AMR) call performanceCS Video call performancePS call performanceISHO performance


Common Call Performance Issues


Behaviour Problem Description Possible solutions

Call set-up failure

Poor coverage area If problem is poor coverage, this means poor RSCP (<-95 dBm) thus also the EcNo degrades very rapidly (< -12 dB) when the coverage border is reached.

Check Antenna line installation (antenna position and quality, cable length and quality).

Call drop Check that CPICH powers are balanced between the studied cells.

Check presence of shadowing obstacles.

Add a site to the area.

Call set-up failure

Poor dominance area.

No main server in the area, too many cells with weak CPICH level.

Use buildings and other environmental structures to isolate cell(s) coverage.

Call drop CPICH EcNo is usually very bad even the RSCP is good e.q. RSCP –80…-90 dBm but EcNo about –10 dB

Down tilt antennas to make cells dominant and limit effects of interfering cell(s).

Check antenna bearing.

Add a site.

Call set-up failure

Pilot Pollution Bad CPICH Ec/Io (<-12 dB) level although CPICH RSCP level is good. High site in the neighbourhood may cause interference.

Find interfering cell from Scanner results.

Call drop Adjust antenna bearing and down tilt or lower the antenna height (too much tilt will break the dominance).

Add interfering cell to the neighbour of the serving cell.

Dropped call/SHO failure Missing neighbour

A good usable neighbour is present within cells coverage area, can cause DL interference if it is not in the active set.

Check scanner data and look for missing neighbours.

Swapped sectors in WBTS. Check the cabling in antenna line.

Call set-up Failure

High PrxTotal due to UL External interference

The PrxTotal level is significantly higher than expected in no/low load conditions.

Try to figure the possible area/direction of the interference by checking PrxTotal level on neighbouring cells.

Call drop Alternatively use spectrum analyser & directive antenna to locate interferer.

Inform operator/regulator about the found conditions.

Check if auto tuning range is large enough (20 dB).

Call set-up failure High PrxToatal due to wrong MHA settings


In case of MHA is used in BTS check MHA and cables loss parameters, otherwise PrxTotal value will be too high.

Call drop MHA settings should be checked, see more in reference(If MHA parameter is set to ON, Cable loss parameter is used, Cable loss = Real MHA gain = Feeder loss parameter)

Call set-up failure High Prxtotal due to Installation problems


Check the antenna installation as the last alternative in high PrxNoise case. Call drop

Cell set-up failure Bad RRC connection set-up success rate due to slow Ue cell reselection

RRC connection set-up complete message not heard by BTS.

Set parameters so that reselection process will start earlier: Qqualmin, Sintrasearch and Qhyst2 as per latest recommendation

Long call set-up time Long time interval for sync between RNC and BTS before connection

The value of Parameter N312 is too high: maximum number of “in sync” indications received from L1 during the establishment of a physical channel

Use smaller value N312 (2, recommendation is 4). Use Actix for checking the call set-up delay (L3 messages). Use call set-up time optimisation feature Dynamic setting of “ActivationTimeOffset” (possible in RAN1.5.2 ED2) enables 200 to 500ms reduction for set up delay.


Common Call Performance Issues


Behaviour Problem Description Possible solutions Dropped call SHO to wrong cell will cause drop

call.Overshooting cell come temporarily into active set and forces a suitable serving cell to be dropped out. Later RSCP suddenly drops in the “wrong cell” and causes a dropped call because there is no neighbour defined.

Pan away overshooting cell if it is too close to the serving cell, otherwise apply down tilting as well.

Dropped call Cell suffering from UL interference = DL (CPICH) coverage much bigger than UL coverage

As the UE Tx power is not enough for target cell synchronisation, the SHO fails which will cause call drop later.

Use cell individual offset (negative value) parameter to balance the DL and UL coverage. Check traffic direction of in-car UEs to decide which cell requires offsets.

Dropped call DL CPICH coverage < UL coverage Cell with lower CPICH power than the surrounding is having “too good” UL performance, as this cells’ UL cannot be used efficiently due to SHO is decided upon DL (CPICH Ec/No).

Use cell individual offset (positive value) parameter to balance the DL and UL coverage.Note: Cell individual offsets are not taken into account when calculating the added cell Tx power.

Dropped call

Round the corner effect

The call drops due to too rapid CPICH coverage degradation for Cell A, and therefore there is not enough time for SHO.

Use cell individual offset (positive value) parameter to balance the DL and UL coverage.Note: Cell individual offsets are not taken into account when calculating the added cell Tx power.

Dropped call/SHO failure Too many neighbours In SHO area the number of combined neighbouring cells become more than 31. HO list is created using RNC algorithm in the final stage some of the neighbours will randomly be removed.

Delete unnecessary neighbours.

Improve dominance.


Video Call Performance Issues


Behaviour Problem Description Possible solutions

Dropped callNot enough DL power to maintain good quality

CS video connection needs more power to maintain the SIR target and thus also BLER target.

Increase the max DL Radio Link power by decreasing the CPICHtoRefRaBOffset In case the max power increment is a lot (~3dB) then the minimum power is increased by 3dB as well which can lead to the minimum power problems (BTS sending too much power to the UEs close to the BTS and therefore causing problems to the UE and even dropped call) Therefore the PCrangeDL parameter should be tuned according to the CPICHtoRefRabOffset parameter tuning (from the default)

Call set-up Failure

High PrxTotal due to UL External interference


Try to figure the possible area/direction of the interference by checking PrxTotal level on neighbouring cells.

Call drop

Alternatively use spectrum analyser & directive antenna to locate interferer. Inform operator/regulator about the found conditions.

Check if auto-tuning range is large enough (20 dB).


ISHO performance


Behaviour Problem Description Possible solutionsCall drop RAN is not working

correctly during SHO.No GSM neighbour list is sent for measurements in case there are 3 cells in Active Set.

This should be corrected in laterRAN release(s).

Call drop Failure to decode BSIC before the call drop.

CM starts too late Set higher ISHO thresholds, FMCS: CPICH EcNo, CPICH RSCP, UE TX Pwr

Call drop Failure to decode BSIC before the call drop.

BSIC verification takes too much time.

Set smaller measurement time for GSM cells, FMCG: Maximum measurement period, Minimum measurement interval,


NETWORK HEALTH CHECK

The Network health check ensures that the planned network is implemented correctly, all cells are up and running and correct parameters are set. These should be done before optimisation. There are many checks to look at: -

Alarm check (BTS, RNC, other)

SW and Parameter check

Neighbour consistency check

Cell load check

KPI check

UE performance check for all the services in a controlled environment

Cell load checksCell load can be checked by looking at the UL interference situation with PrxNoise counter in each cell. Normally the PrxNoise is around –102…-105 dBm, but if it is more than this, there is something wrong in the cell. The reason could be external interference, or incorrect MHA parameters.The total load in UL and DL (PtxTotal, PrxTotal) should be less than (PtxTarget, PrxTarget), otherwise the cell is overloaded.


KPI / Performance Analysis




Major RS reports for Performance analysis


Report Name DescriptionRSRAN000 System_Program_RNC_Level_DailyRSRAN018 Inter System_Handover_ReasonsRSRAN019 Inter System_Handover_per_CauseRSRAN023 Inter System_Handover_PerformanceRSRAN044 IFHO_AdjacenciesRSRAN045 ISHO_AdjacenciesRSRAN046 SHO_AdjacenciesRSRAN066 Node_B_Capacity DailyRSRAN067 Cell_Capacity_dailyRSRAN068 RNC_Capacity_DailyRSRAN068 RNC_Capacity_HourlyRSRAN070 Allocated_Traffic_Amounts_(R99_+_HSPA)_DailyRSRAN073 Service_Session_Accessibility_Analysis_DailyRSRAN079 Service_Session_Retainability_Analysis_DailyRSRAN084 System_Program_Cell_Level_Daily.xls


Various Reporting-Suit reports for KPI analysis


Sl.No 3G RAN Reports Report Name

Object Type Object Aggregation

1 System Program RSRAN000 PLMN RNC2 System Program RSRAN084 PLMN WCEL

3 Capacity RSRAN066, RSRAN067, RSRAN068,RSRAN087,RSRAN085 PLMN WBTS,WCEL,RNC & IuB

4 Capacity RSRAN066, RSRAN067, RSRAN068,RSRAN087,RSRAN085 PLMN WBTS,WCEL,RNC & IuB5 Service Level RSRAN073, RSRAN079,RSRAN101 PLMN PLMN,RNC6 Service Level RSRAN073, RSRAN079,RSRAN101 PLMN WCEL,RNC7 Traffic RSRAN070, RSRAN077 PLMN WCEL8 Traffic RSRAN070, RSRAN077, RSRAN088 PLMN WCEL, RNC

9 Mobility & Handover

RSRAN033, RSRAN018, RSRAN019,

PLMN WCELRSRAN023, RSRAN044, RSRAN045,RSRAN046, RSRAN028

10 Mobility & Handover

RSRAN033, RSRAN018, RSRAN019,

PLMN WCELRSRAN023, RSRAN044, RSRAN045,RSRAN046, RSRAN028

11 HSPARSRAN051, RSRAN039, RSRAN092, RSRAN091, RSRAN041, RSRAN074, RSRAN090, RSRAN034, RSRAN075,RSRAN040 PLMN WCEL

12 HSPARSRAN051, RSRAN039, RSRAN092, RSRAN091, RSRAN041, RSRAN074, RSRAN090, RSRAN034, RSRAN075,RSRAN040 PLMN WCEL

13 Signalling RSRAN027, RSRAN038 PLMN WCEL14 Signalling RSRAN027, RSRAN038 PLMN WCEL

15PRACH Propagation Delay RSRAN104 PLMN WCEL

16 Ec/No Distribution RSRAN028 PLMN WCEL17 Prx Distribution RSRAN067 PLMN WCEL18 Ptx Distribution RSRAN067 PLMN WCEL19 RNC Hardware RSRAN102 PLMN RNC/DSPPID

20Customized XML file / Raw Counters

If customised reports required for Assessment are not available with Local engineer, we can extract that information by uploading customised reports in OSS.


Call Setup failures for Voice and PacketRRC connection setup

RAN resources are reserved for signaling connection between UE and RNC

RRC accessConnection between UE and RRC

RRC activeUE has RRC connection. If dropped, also active RAB is dropped.

RAB setupAttempts to start the call

RAB setup access

RAB active phaseUE has RAB connection

CSSR For Voice affected if any of the followings take place.

RRC Conn. Setup Fail

RRC Conn. Access Fail

RAB Setup Fail

RAB Setup Access Fail

Setup

Complete

Setup

Complete

Access

Complete

Access

Complete

Active

Complete

Active

Complete

SetupSetup AccessAccess ActiveActive

Att

em

pts

Setup failures(blocking)

Access failures

Access

Active

Release

Active

Release

Active

Failures

Active

Failures

RRCDrop

Su

ccess

Phase:

RRC and RAB phases


Call/packet Setup improvement• RRC/RAB/PS call Setup & Access Analysis Process Flow Chart

Sites OK ?

Cell and Neighbour Cells availability

Alarms/Tickets

Setup /Access

Yes

Setup /Access

Setup Failure Cause?

Capacity Optimisation

BTS/TRANS/FROZBSUL/DL Interference (DL codes)

AC

Troubleshooting

RNC

RF Optimisation

Top (N) RRC Setup and Access failures

Top (N) RAB Setup/Access or PS Setup failures

Coverage/Interference

setup

setup

Interference

Coverage

3G cell at inter-RNC border ?

SRNS Relocation/Iur troubleshooting

Yes

NO

Access

Setup/Access

SHO based on DSR, CPICH EcNo difference

RAB/DCH setup &failures, UL coverage counters to see UL spikes

RRC_setup/SRB_act fails, RB_setup failures for HSDPA

DCH reconfiguration failures AC/BTS/trans

SHO branch setup fail BTS/Iub, RNC capacity SW, new DSP counters

Rej_DCH_due to power or codes (UL/DL)

RAB setup fail voice Iur/trans, DCH setup failure for NRT in Iur

Fail_MAC_d_setup_HSDPA


Low CSSR• RRC Setup Analysis

1. Check the problem cells and its neighbouring cells of any faulty alarms

2. Identify root cause failure distribution using Service Report -> RSRAN0733. RRC_CONN_STP_FAIL_AC

Check UL Interference, DL Power & Code occupancy if there is need to upgrade radio capacity

UL Power Spikes -> Disable UL Admission Control to if the number of failures is critical (Prxtarget ->30 dB)

M1002C1 CH_REQ_LINK_REJ_UL_SRNC ----> Evaluate Prx Resource Problem

M1002C2 CH_REQ_LINK_REJ_DL_SRNC ----->Evaluate Ptx Resource Problem

4. RRC_CONN_STP_FAIL_BTS

Evaluate NBAP counters (radio link reconf. Failures) and KPIs for troubleshooting BTS resources

Check BTS configuration in terms of WAM and CE allocation – Use Channel Element (5001) Counters in order to

evaluate lack of Channel Elements (more info in RSRAN066)

Expand the Capacity or decrease the traffic offered to the site

In case BTS is not responding delete and re-create COCO

5. RRC_CONN_STP_FAIL_TRANS

Evaluate Number of reconfiguration failure due the transmission

Check COCO Configuration

Use AAL2 Mux in case of two WAM

Expand the Iub capacity or decrease the traffic offered to the site

6. RRC_CONN_STP_FAIL_RNC

Typically RNC fault or Incoming SRNC Relocation Failure (inter-RNC border)

Required ICSU log tracing if no RNC fault or SRNC relocation problem


Low CSSR

• RRC Access Analysis 7. RRC_CONN_ACC_FAIL_RADIO

This is quite Dominant failure cause in case of sync. problems

This could happen in Coverage border

UL Coverage -> Decrease Cell Coverage (higher RxlevMin) if the cause is UL interference

DL Coverage-> Increase Cell Coverage max :CPICHToRefRABOffset (2->0 dB)

Service Level -> RSRAN073

NBAP: Synchronisation Indication

L1 Synchronisation


L1 Synchronisation

RRC: RRC ConnectionSetupComplete (DCH) X

UE

BTS

RNC

XRRC Access Failures for L1 synchronization


L1 Synchronisation


L1 Synchronisation

RRC: RRC ConnectionSetupComplete (DCH)

XUE

BTS

RNC

RRC Access Failures due to MS

Cell Reselections (no error)

RRC_CONN_ACC_FAIL_MS

UL Coverage -> Tune Cell Dominance (or CPICH) in order to balance UL and DL (if UL interference if not the cause)


Low CSSR : Propagation delay

• RRC Access Analysis

9. If RRC setup/access failure due to Radio/MS, it is also possible to check whether UEs are located at distance area or close to cell edge area

Propagation delay counters from RRC measurement M1006C128-C148 reports call setup distance during RRC connection request or cell update This give hints that either cells has large coverage area (tall sites with over-shooting) or non-optimum cell coverage from neighbouring cells

0

100000

200000

300000

400000

500000

600000

0.00%

20.00%

40.00%

60.00%

80.00%

100.00%

120.00%

average

CDF


Low CSSR: UL interference counters

• 10. From RU10, new coverage counters (RAN1630) for total uplink power (RTWP) measurement also can be used to identify RRC setup/access fail due to AC/Radio/MS.

– All the received power is taken into account, not just Rel99– These counters could be used to see UL interference in the cell

M1000C320 Cell_Resource RTWP_CLASS_0M1000C321 Cell_Resource RTWP_CLASS_1M1000C322 Cell_Resource RTWP_CLASS_2M1000C323 Cell_Resource RTWP_CLASS_3M1000C324 Cell_Resource RTWP_CLASS_4M1000C325 Cell_Resource RTWP_CLASS_5M1000C326 Cell_Resource RTWP_CLASS_6M1000C327 Cell_Resource RTWP_CLASS_7M1000C328 Cell_Resource RTWP_CLASS_8M1000C329 Cell_Resource RTWP_CLASS_9M1000C330 Cell_Resource RTWP_CLASS_10M1000C331 Cell_Resource RTWP_CLASS_11M1000C332 Cell_Resource RTWP_CLASS_12M1000C333 Cell_Resource RTWP_CLASS_13M1000C334 Cell_Resource RTWP_CLASS_14M1000C335 Cell_Resource RTWP_CLASS_15M1000C336 Cell_Resource RTWP_CLASS_16M1000C337 Cell_Resource RTWP_CLASS_17M1000C338 Cell_Resource RTWP_CLASS_18M1000C339 Cell_Resource RTWP_CLASS_19M1000C340 Cell_Resource RTWP_CLASS_20M1000C341 Cell_Resource RTWP_CLASS_21

0.00

200.00

400.00

600.00

800.00

1 000.00

1 200.00

1 400.00

RTW P_CLASS_14 (M1000C334, -92..-89 dBm) RTWP_CLASS_15 (M1000C335, -89..-86 dBm)

RTW P_CLASS_16 (M1000C336, -86..-83 dBm ) RTWP_CLASS_17 (M1000C337, -83 dBm..-80 dBm)

RTW P_CLASS_18 (M1000C338, -80..-75 dBm) RTWP_CLASS_19 (M1000C339, -75..-70 dBm)

RTW P_CLASS_20 (M1000C340, -70..-65 dBm) RTWP_CLASS_21 (M1000C341, > -65 dBm)

RRC Access Analysis

Temporary High UL interference: class_21 could be seen


Low CSSR

With RU10, there is new counters to measure the setup success of standalone Signaling Radio Bearers (SRBs). Standalone SRB means a successfully established RRC connection that is waiting for the RAB assignment

SRB active fail is pegged when RNC sent RRC:RRC connection Release before RAB assignment With RNC_1219a, this give better visibilities where low CSSR is somehow caused by failure in

active standalone SRB phase



Low CSSR• AMR RAB setup/access Analysis

1. Check the problem cells and its neighbouring cells of any faulty alarms

2. Identify root cause failure distribution and main failure contributor using Services -> RSRAN073

3. RAB_STP_FAIL_XXX_AC

Check UL Interference, DL Power & Code occupancy if there is need to upgrade radio capacity

REQ_CS_VOICE_REJ_UL_SRNC -> Evaluate Prx cell resource

REQ_CS_VOICE_REJ_DL_SRNC -> Evaluate Ptx cell resource

NO_CODES_AVAILABLE_SF128/SF32 -> Evaluate AMR voice / PS64 code congestion

Check parameter setting with UL throughput based AC and power based AC

4. RAB_STP_FAIL_XXX_BTS

Evaluate NBAP counters (radio link reconf. Add failures) and KPIs for troubleshooting BTS resources

Check BTS configuration in terms of WAM and CE allocation – Use Channel Element (5001) Counters in order to evaluate lack of Channel Elements

Expand the Capacity or decrease the traffic offered to the site

5. RAB_STP_FAIL_XXX_TRANS

Evaluate Number of reconfiguration failure due the transmission

Check M1005C128 CANC_ADD_SRNC_TRAN_STP_FAIL

Check RAB_STP_FAIL_XXX_IUB_AAL2, M1001C531-C533

6. RAB_ACC_FAIL_XXX_UE

Evaluate Cell resource Prx and Ptx (for example high uplink interference)

Check RB reconfiguration failure ration ( If offset for activation time (RNC) setting is insufficient – recommmended is 500-700ms )

7. RAB_ACC_FAIL_XXX_RNC

Typically RNC fault or Incoming SRNC Relocation Failure (inter-RNC border)

Required ICSU log tracing if no RNC fault or SRNC relocation problem



Low CSSR• AMR RAB Setup/Access Analysis

8. RAB_Setup_FAIL_CS_Voice_LIC

Counter incremented when the RNC rejects a CS Voice RAB request due to AMR capacity license Exceeded (only for RNC2600)

9. RAB_Setup_FAIL_CS_Voice_Iur_TRCounter incremented when a CS voice traffic class RAB setup fails due to Iur transport resources shortage

10. RAB_Setup_FAIL_CS_Voice_Iu_CS

Counter incremented when a CS voice traffic class RAB setup fails due to Iu-CS transport resources

Service -> RSRAN073


Low CSSR• Rel99 NRT RAB Setup Success Analysis

There is two ways to evaluate the Rel99 NRT RAB setup success performance M1001, RNC_576e Packet Service Setup Success Ratio (CSSR) / CSSR PS NRT M1022, RNC_943a R99 Setup Success Ratio from user perspective for NRT/ R99 stp SR Usr

Since RNC_576c (M1001) is measured NRT DCH setup upto 0/0kbps, it is always showing >99.5%. So it is not useful for data call setup analysis Packet calls starts with user plane capacity allocation (transfer from FACH/PCH, DCH 0/0) and ends with dedicated resource release (transfer back to FACH/PCH, DCH 0/0, RAB release, outgoing relocation, HHO, ISHO)

Service -> RSRAN073

M1001 M1022


Low CSSR• Rel99 NRT RAB Setup Success Analysis

With RU10, there is new counters which gives better visibilities in terms of Rel99 NRT DCH setup failure causes (DCH0/0 -> DCH x/x kbps or DCH upgrade request) The number of NRT DCH setup rejects for interactive/BG traffic class due to running out of channelisation codes in DL and power in DL/UL (This counter includes initial DCH setups, handover attempts and channel type switches from HS-DSCH to DCH)The number of NRT DCH reconfiguration rejects (bitrate upgrade) for interactive/BG traffic class due to running out of channelizatin codes in DL and power in DL/UL Iur resources setup fails during user plane allocation/modification of PS NRT RAB over IUR branch

M1002C553 Traffic REJ_DCH_DUE_CODES_INT_DLM1002C554 Traffic REJ_DCH_DUE_CODES_BGR_DLM1002C555 Traffic REJ_DCH_DUE_POWER_INT_DLM1002C556 Traffic REJ_DCH_DUE_POWER_BGR_DLM1002C557 Traffic REJ_DCH_REC_DUE_CODES_INT_DLM1002C558 Traffic REJ_DCH_REC_DUE_CODES_BGR_DLM1002C559 Traffic REJ_DCH_REC_DUE_PWR_INT_DLM1002C560 Traffic REJ_DCH_REC_DUE_PWR_BGR_DL

M1002C626 Traffic REJ_DCH_DUE_POWER_INT_ULM1002C627 Traffic REJ_DCH_DUE_POWER_BGR_ULM1002C628 Traffic REJ_DCH_REC_DUE_PWR_INT_ULM1002C629 Traffic REJ_DCH_REC_DUE_PWR_BGR_UL

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

1 11 21 31 41 51 61 71 81 91 101 111 121 131 141 151 161

max

, ave

occ

upan

cy &

blo

ckin

g (%

)

0.00

50.00

100.00

150.00

200.00

250.00

300.00

RNC_11a_Average code occupancy RNC_520b_Max Occupancy RNC_949a Code blocking rate

Rej DCH due codes Rej DCH REC due codes

Reconfig reject due to lack of codes

M1004C165 FAIL_NRT_DCH_SETUP_IURNRT DCH SETUP FAIL DUE TO IUR

M1004C166FAIL_NRT_DCH_UL_RECONF_IUR

NRT DCH UL RECONFIG FAIL FOR NRT RB DUE TO IUR

M1004C167FAIL_NRT_DCH_DL_RECONF_IUR

NRT DCH DL RECONFIG FAIL FOR NRT RB DUE TO IUR


Low Packet/session success rate (SSSR)Service -> RSRAN073

Rel99 Packet session setup failures Analysis (M1022)

Evaluate Dominant failures:

AC failure : lack of DL power or high UL interference, UL admission control parameter setting

Other failure: This could be due to max HSPA users limit reached or “radio link failure” during setup

BTS failure: lack of HW CE capacity

DMCU failure: DMCU/DSP faulty or lack of DSP resources in RNC

TRANS failure: lack of Iub capacity

UE failure: UE internal problem (not capability issue)

Cannot differentiate Rel99 DCH , HSDPA,

HSUPA setup failure

_DCH_BGRPS_ATT_DCH M1022C8 +_DCH_INTPS_ATT_DCH M1022C7

D_ALLO_BGRD_D_REQ_D_ M1022C32 +D_ALLO_INTD_D_REQ_D_ M1022C31100

_DCH_BGRPS_ATT_DCH M1022C8 +_DCH_INTPS_ATT_DCH M1022C7

D_ALLO_BGRD_D_REQ_D_ M1022C32 +D_ALLO_INTD_D_REQ_D_ M1022C31100 Check KPI RNC_943a for low Rel99 packet SSSR


Low Packet/session success rate (SSSR)

M1022 Rel99 Packet session setup failures Analysis In RU10, new counters to identify the Rel99 NRT DCH setup and successful setup based on

initial request bit rates or DCH upgrade bit rates Uplink initial request and success include also HSDPA UL return channel This is useful to identify each of the bit rate setup performance and its distribution as well as

capacity bottleneckM1022C83 Packet_call INIT_DCH_REQ_64_ULM1022C84 Packet_call INIT_DCH_REQ_64_DLM1022C85 Packet_call INIT_DCH_REQ_128_ULM1022C86 Packet_call INIT_DCH_REQ_128_DLM1022C87 Packet_call INIT_DCH_REQ_256_ULM1022C88 Packet_call INIT_DCH_REQ_256_DLM1022C89 Packet_call INIT_DCH_REQ_384_ULM1022C90 Packet_call INIT_DCH_REQ_384_DL

M1022C91 Packet_call DCH_UPGR_REQ_64_ULM1022C92 Packet_call DCH_UPGR_REQ_64_DLM1022C93 Packet_call DCH_UPGR_REQ_128_ULM1022C94 Packet_call DCH_UPGR_REQ_128_DLM1022C95 Packet_call DCH_UPGR_REQ_256_ULM1022C96 Packet_call DCH_UPGR_REQ_256_DLM1022C97 Packet_call DCH_UPGR_REQ_384_ULM1022C98 Packet_call DCH_UPGR_REQ_384_DL

M1022C99 Packet_call SUCC_INIT_ALLO_64_ULM1022C100 Packet_call SUCC_INIT_ALLO_64_DLM1022C101 Packet_call SUCC_INIT_ALLO_128_ULM1022C102 Packet_call SUCC_INIT_ALLO_128_DLM1022C103 Packet_call SUCC_INIT_ALLO_256_ULM1022C104 Packet_call SUCC_INIT_ALLO_256_DLM1022C105 Packet_call SUCC_INIT_ALLO_384_ULM1022C106 Packet_call SUCC_INIT_ALLO_384_DL

M1022C107 Packet_call SUCC_INIT_ALLO_REQ_64_ULM1022C108 Packet_call SUCC_INIT_ALLO_REQ_64_DLM1022C109 Packet_call SUCC_INIT_ALLO_REQ_128_ULM1022C110 Packet_call SUCC_INIT_ALLO_REQ_128_DLM1022C111 Packet_call SUCC_INIT_ALLO_REQ_256_ULM1022C112 Packet_call SUCC_INIT_ALLO_REQ_256_DLM1022C113 Packet_call SUCC_INIT_ALLO_REQ_384_ULM1022C114 Packet_call SUCC_INIT_ALLO_REQ_384_DL

M1022C115 Packet_call SUCC_UPG_NRT_DCH_64_ULM1022C116 Packet_call SUCC_UPG_NRT_DCH_64_DLM1022C117 Packet_call SUCC_UPG_NRT_DCH_128_ULM1022C118 Packet_call SUCC_UPG_NRT_DCH_128_DLM1022C119 Packet_call SUCC_UPG_NRT_DCH_256_ULM1022C120 Packet_call SUCC_UPG_NRT_DCH_256_DLM1022C121 Packet_call SUCC_UPG_NRT_DCH_384_ULM1022C122 Packet_call SUCC_UPG_NRT_DCH_384_DL

M1022C123 Packet_call SUCC_UPG_NRT_DCH_REQ_64_ULM1022C124 Packet_call SUCC_UPG_NRT_DCH_REQ_64_DLM1022C125 Packet_call SUCC_UPG_NRT_DCH_REQ_128_ULM1022C126 Packet_call SUCC_UPG_NRT_DCH_REQ_128_DLM1022C127 Packet_call SUCC_UPG_NRT_DCH_REQ_256_ULM1022C128 Packet_call SUCC_UPG_NRT_DCH_REQ_256_DLM1022C129 Packet_call SUCC_UPG_NRT_DCH_REQ_384_ULM1022C130 Packet_call SUCC_UPG_NRT_DCH_REQ_384_DL


Low Packet/session success rate (SSSR)

In RU10, new counters also to identify the Rel99 NRT DCH Reconfiguration failure during initial request (DCH0/0 to DCH x/x kbps or cell Fach to DCH) and bit rate upgrade request

Also HSDPA uplink allocations update these counters

M1022C139 FAIL_REC_INTERA_DCH_UL_ACDCH UPLINK RECONFIG FAIL DUE TO AC FOR INTERACTIVE

M1022C140 FAIL_REC_BGR_DCH_UL_ACDCH UPLINK RECONFIG FAIL DUE TO AC FOR BACKGROUND

M1022C141 FAIL_REC_INTERA_DCH_DL_ACDCH DOWNLINK RECONFIG FAIL DUE TO AC FOR INTERACTIVE

M1022C142 FAIL_REC_BGR_DCH_DL_ACDCH DOWNLINK RECONFIG FAIL DUE TO AC FOR BACKGROUND

M1022C135 FAIL_REC_INTERA_DCH_UL_BTSDCH UPLINK RECONFIG FAIL DUE TO BTS FOR INTERACTIVE

M1022C136 FAIL_REC_BGR_DCH_UL_BTSDCH UPLINK RECONFIG FAIL DUE TO BTS FOR BACKGROUND

M1022C137 FAIL_REC_INTERA_DCH_DL_BTSDCH DOWNLINK RECONFIG FAIL DUE TO BTS FOR INTERACTIVE

M1022C138 FAIL_REC_BGR_DCH_DL_BTSDCH DOWNLINK RECONFIG FAIL DUE TO BTS FOR BACKGROUND

M1022 Rel99 Packet session setup failures Analysis

M1022C131 FAIL_REC_INTERA_DCH_UL_TRANSDCH UPLINK RECONFIG FAIL DUE TO TRANSPORT FOR INTERACTIVE

M1022C132 FAIL_REC_BGR_DCH_UL_TRANSDCH UPLINK RECONFIG FAIL DUE TO TRANSPORT FOR BACKGROUND

M1022C133 FAIL_REC_INTERA_DCH_DL_TRANSDCH DOWNLINK RECONFIG FAIL DUE TO TRANSPORT FOR INTERACTIVE

M1022C134 FAIL_REC_BGR_DCH_DL_TRANSDCH DOWNLINK RECONFIG FAIL DUE TO TRANSPORT FOR BACKGROUND

M1022C143 FAIL_REC_INTERA_DCH_UL_OTHDCH UPLINK RECONFIG FAIL DUE TO OTHER REASONS FOR INTERACTIVE

M1022C144 FAIL_REC_BGR_DCH_UL_OTHDCH UPLINK RECONFIG FAIL DUE TO OTHER REASONS FOR BACKGROUND

M1022C145 FAIL_REC_INTERA_DCH_DL_OTHDCH DOWNLINK RECONFIG FAIL DUE TO OTHER REASONS FOR INTERACTIVE

M1022C146 FAIL_REC_BGR_DCH_DL_OTHDCH DOWNLINK RECONFIG FAIL DUE TO OTHER REASONS FOR BACKGROUND

0.00

200.00

400.00

600.00

800.00

1 000.00

1 200.00

1 400.00

1 600.00

1 800.00

2 000.00

1 10 19 28 37 46 55 64 73 82 91 100 109 118

FAIL_REC_BGR_DCH_DL_TRANS

FAIL_REC_INTERA_DCH_DL_TRANS

FAIL_REC_INTERA_DCH_DL_BTS

FAIL_REC_BGR_DCH_DL_BTS

FAIL_REC_INTERA_DCH_DL_AC

FAIL_REC_BGR_DCH_DL_AC

FAIL_REC_INTERA_DCH_DL_OTH

FAIL_REC_BGR_DCH_DL_OTH

In DL, Failures mainly from AC (Interactive and Background)


Call/Packet Drop improvement in RU10Top (N) drops

Cell and its Neighbour Cells availabilityAlarms/Tickets

Configuration & Parameter audit

SHO Success Rate < 90%?

Conf OK ?

Site OK ?

ISHO Failures

Iur

performanceInvestigation Iur

Audit adjacent sites for alarms, Availability, configuration and capacity

TrafficNeighbours’ Performance (use SHO success per adjs counters to identify badly performing neighbours) & Map

3G Cell at RNC border?

NO

YES

New site ?

Analyse last detailed radio measurements

RF and IFHO neighbour optimisation

No cell found ratio >40 %

ISHO Success Rate < 90%

RF and ISHO neighbour optimisation

3G cell covers over a coverage hole ?

3G cell at inter-RNC border ?

Wrong reference clock (10MHz tuning)

No cell found ratio > 90 % and enough ADJG

2G Cell Doctor

2G Investigation : TCH blocking or TCH seizure failure (interference)

NO

YES

YES

YES

NO

YES

NO

YES

YES

SHO

ISHO

Top issues

SHO based on DSR, CPICH EcNo difference, SHO branch setup fail BTS/Iub

Relocation success in target RNC

HHO RSSI & BSIC time, ISHO cancellation

Max HSPA users in cell/RNC,RNC licensed capacity:Max AMR/Iups throughput

HSDPA IFHO failures, reject CM for IFHO


High in AMR / Rel99 NRT call drop rate?1. Check if low RNC_231c RAB Success Ratio, Voice (CSR) cells and low RNC_571b

RAB retainability for PS cells and its neighbouring cells of any faulty alarms2. Identify call drop root cause failure distribution and main failure contributor (radio,

Iu, BTS, Iur, MS, RNC) – Services -> RSRAN079

• 3. Check SHO KPI if performance < 90% ( leads to radio failure)• Check if cells are at RNC border (check Iur capacity and SRNC relocation problem)• Detect badly performing neighbours using HO success rate per adjacency counters (M1013)• High incoming HO failure rate in all adjs – check sync alarms• Assessing neighbor list plan and visualization check with map• Evaluate HO control parameters and trigger threshold

• 4. Check ISHO KPI if RT ISHO < 90% or NRT < 80% (leads to radio failure)• Check missing neighbour (M1015), GSM frequency plan neighbour RNC and MSC database

consistency audit, check alarm of reference clock in 3G or in 2G, check 2G TCH congestion• Check RRC Drop ISHO RT / NRT


High in AMR / Rel99 NRT call drop rate?

• 5. Detecting DL or UL path loss problem if RAB drop due to radio (dominant call

• drop cause > 50%)• Check UL Lost Active KPI from Iub counters (active L1 synchronization failure) to check UL/DL

path loss problem

• Check ASU failure rate (UNSUC_ASU) which link to NO RESPONSE FROM RLC

• Mapping radio failures with Tx power and CPICH related parameters -> CPICHToRefRABOffset, PTXDPCH MAX

• Check Call reestablishment timer -> T315 for NRT and T314 for RT reestablishment

• Ecno distribution for bad coverage issue (M1007C38-M1007C47)

• 6. Check core network parameter setting if RAB_ACT_FAIL_XXX_IU• Check SCCP SGSN/RNC IuPS Tias/Tiar if RAB_ACT_FAIL_BACKG_IU

• 7. If high RAB_ACT_FAIL_XXX_BTS• Check if any BTS faulty alarm (7653 cell faulty alarm)

• If no alarms, COCO detach/attach

• 8. If high RAB_ACT_FAIL_XXX_MS• Check physical channel reconfiguration failure rate (IFHO, ISHO, code optimisation)

Services -> RSRAN079


High in AMR / Rel99 NRT call drop rate?SHO -> RSRAN028

9. SHO failure Analysis in RU10

Two new counters to identify SHO failure due to lack of Iub capacity or BTS HW CE capacity

RU10 also brings new counters to identify Ecno difference between source – target cell pairs and average Ecno, average RSCP for the neighbour cells based on scrambling codes

Counters updated if RAN1191 Detected Set Reporting and Measurements and RAN1189 CPICH Ec/N0 Difference Counters per Cell Pair feature is licensed

M1007C71SETUP_FAIL_SHO_BRANCH_BTS : When the SHO branch setup fails due to BTS resources. The BTS resources here mean either NBAP: RADIO LINK SETUP FAILURE, NBAP: RADIO LINK ADDITION FAILURE or that RNC does not receive any answer from the BTS. The counter is updated for the cell where the failure occurred.

M1007C72 SETUP_FAIL_SHO_BRANCH_IUB :. When the SHO branch setup fails due to Iub transport. The transport failures include both CAC (Connection Admission Control) negative acknowledgements and signaling failures.

M1007C71SETUP_FAIL_SHO_BRANCH_BTS : When the SHO branch setup fails due to BTS resources. The BTS resources here mean either NBAP: RADIO LINK SETUP FAILURE, NBAP: RADIO LINK ADDITION FAILURE or that RNC does not receive any answer from the BTS. The counter is updated for the cell where the failure occurred.

M1007C72 SETUP_FAIL_SHO_BRANCH_IUB :. When the SHO branch setup fails due to Iub transport. The transport failures include both CAC (Connection Admission Control) negative acknowledgements and signaling failures.

M1013C2 AutoDef_SHO_v2 CPICH_ECNO_SHO_DIFF_SUMM1013C3 AutoDef_SHO_v2 CPICH_ECNO_SHO_DIFF_DENOM

M1013C4 AutoDef_SHO_v2 CPICH_ECNO_SHO_SUMM1013C5 AutoDef_SHO_v2 CPICH_ECNO_SHO_DENOMM1013C6 AutoDef_SHO_v2 CPICH_RSCP_SHO_SUMM1013C7 AutoDef_SHO_v2 CPICH_RSCP_SHO_DENOM

M1028C0 Autodef_SHO_DSR CPICH_ECNO_DET_SUMM1028C1 Autodef_SHO_DSR CPICH_ECNO_DET_DENOMM1028C2 Autodef_SHO_DSR CPICH_RSCP_DET_SUMM1028C3 Autodef_SHO_DSR CPICH_RSCP_DET_DENOM



10. Drop due to Radio Analysis in RU10

RU10 brings in new feature for RRC Re-establishment for RT and Multi-RAB

This feature is associated with parameter T314 and RT call re-establishment is “on” when T314> 0s. Generally, AMR drop call rate in OSS stats will greatly improved

New counters to measure the performance of call re-establishment for RT & Multi-RAB

M1006C186 RRC RRC_RE_EST_SUCC_RTM1006C187 RRC RRC_RE_EST_FAIL_UE_RTM1006C188 RRC RRC_RE_EST_FAIL_NOREPLY_RTM1006C189 RRC RRC_RE_EST_SUCC_MRM1006C190 RRC RRC_RE_EST_FAIL_UE_MRM1006C191 RRC RRC_RE_EST_FAIL_NOREPLY_MR



KPI Rel99 NRT DCH Drop Call Rate from Packet Call (M1022)

M_D_D_BGRPS_REL_NOR M1022C50M_D_D_INTPS_REL_NOR M1022C49

BGR_FAIL_D_D_PS_REL_OTH M1022C68INT_FAIL_D_D_PS_REL_OTH M1022C67

GRFAIL_D_D_BPS_REL_RL_ M1022C62NTFAIL_D_D_IPS_REL_RL_ M1022C61BGR_FAIL_D_D_PS_REL_OTH M1022C68INT_FAIL_D_D_PS_REL_OTH M1022C67

GRFAIL_D_D_BPS_REL_RL_ M1022C62NTFAIL_D_D_IPS_REL_RL_ M1022C61

[%] ePerspectiv User End from Ratio SuccessR99 RNC_944a

1





[%] ePerspectiv User End from Ratio SuccessR99 RNC_944a

1





[%] ePerspectiv User End from Ratio Call Dropped R99





[%] ePerspectiv User End from Ratio Call Dropped R99


Low HSDPA Accessibility

• HSDPA Accessibility failure cause analysis can be done with traffic measurements (RNC_605b) and Packet call measurements (RNC_914b)

System Program – RNC_605a

Service Level –RNC_914a

Low HSDPA accessibility (RNC_605b)

Check Number of simultaneous HSDPA users in BTS or cell level depending on the scheduler type

Check BH Channel Element resource Usage

(Lack of CE for UL return Channel)

Check BH UL Power Congestion

(Lack of Radio resources for UL return Ch.)

Check BH AAL2 Iub congestion

(Lack of Iub resources for UL return Ch.)

Check RB reconfiguration failure rate

(Terminal Problem)

Check RNC Unit load (DMPG), max number of users/RNC, DSP failures and faulty alarms

No Action Needed

Too many HSDPA users reached

HSDPA Setup Fail due BTS

Rejection of UL Return Channel Rejections

HSDPA Setup Fail Iub (Both UL & DL)

HSDPA Setup Fail UE

HSDPA Setup Fail RNC Internal

No

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

No

No

No

No

Based on Traffic measurement analysis (M1002)



PS Setup Failure due AC

Low HSPA Setup Performance (RNC_914b) Yes

No

Air Interface

PS Setup Failure due BTS

Yes

No

BTS

PS Setup Failure due Iub

Yes

No

Iub

PS Setup Failure due to, DMCU

YesRNC

Problem In

PS Setup failure due to

Others

No

Yes High Traffic Event

Yes

RSRAN073

PS Setup failure due to

UE

No action needed

Terminal Issue?

HSDPA Accessibility failure analysis based on Packet Call Measurement (M1022)

Others failure could be max HSPA users been reached or “radio link failure” during setup

If not DMCU faulty, check DSP resource usage and availability with RU10 M609 DSP Service Stats and M615 DSP Resource.


Low HSDPA Accessibility With RU10, there is new counters in packet call to identify packet call attempt to cells which

are not HSPA enabled. New KPI (RNC_914b) gives better results in terms of HSDPA accessibility when networks mixed with HSPA and non-HSPA enabled cells. This avoids separate aggregation which required previously in RAS06.

RNC_914b does not include statistics from serving cell change mobility. Thus, the performance could be lower as well due to statistical calculation

RNC_914b: (NetAct names)

100* sum(HS_E_REQ_HS_E_ALLO_INT + HS_E_REQ_HS_E_ALLO_BGR + HS_E_REQ_HS_D_ALLO_INT + HS_E_REQ_HS_D_ALLO_BGR + HS_D_REQ_HS_D_ALLO_INT + HS_D_REQ_HS_D_ALLO_BGR) / sum(PS_ATT_HSDSCH_EDCH_INT + PS_ATT_HSDSCH_EDCH_BGR + PS_ATT_HSDSCH_DCH_INT + PS_ATT_HSDSCH_DCH_BGR - HS_D_REQ_D_D_ALLO_BGR_CELL - HS_D_REQ_D_D_ALLO_INT_CELL - HS_E_REQ_D_D_ALLO_BGR_CELL - HS_E_REQ_D_D_ALLO_INT_CELL)

RNC_605b: (NetAct names)

100* sum(ALLO_HS_DSCH_FLOW_INT+ALLO_HS_DSCH_FLOW_BGR) / sum(ALLO_HS_DSCH_FLOW_INT + ALLO_HS_DSCH_FLOW_BGR + REJ_HS_DSCH_RET_INT + REJ_HS_DSCH_RET_BGR + SETUP_FAIL_RNC_HS_DSCH_INT + SETUP_FAIL_BTS_HS_DSCH_INT + SETUP_FAIL_IUB_HS_TOTAL_INT + SETUP_FAIL_RNC_HS_DSCH_BGR + SETUP_FAIL_BTS_HS_DSCH_BGR + SETUP_FAIL_IUB_HS_TOTAL_BGR + SETUP_FAIL_UE_HS_DSCH_INT + SETUP_FAIL_UE_HS_DSCH_BGR + DCH_SEL_MAX_HSDPA_USERS_INT + DCH_SEL_MAX_HSDPA_USERS_BGR)

The number of DCH/DCH allocations after an HS-DCSH/E-DCH request for the background traffic class due to the cell not supporting HSUPA and HSDPA


1. Identify root cause of failure distribution and main failure contributor

• 2. If high HSDPA Access Failure _too many HSDPA users – Check simultaneous HSDPA users (RNC_646c to RNC_654c) & (RNC_1028b to

RNC_1035b) & (RNC_1665a to RNC_1668a) – RU10 new counters on max & average HSPA users

• 3. If high HSDPA Access Failure_UL DCH – Rejected HS-DSCH return channel due to lack of radio power resource – Check M1002C521 or M1002C522 or M1000C144 – only when HSDPA static allocation– Check Cell resource PrxTotal, PtxTotal– Check parameter setting for uplink throughput based and interference based admission

control

• 4. If high HSDPA Access Failure_UE– Check RB reconfiguration failure rate– ICSU log for UE types troubleshooting ?– RU10 new counters to measure HSDPA setup success in RB reconfiguration phase

Low HSDPA AccessibilityService level -> RSRAN073

M1000C282 Cell_Resource MAX_HSDPA_USERS_IN_CELLM1000C283 Cell_Resource MAX_HSUPA_USERS_IN_CELLM1000C284 Cell_Resource SUM_HSDPA_USERS_IN_CELLM1000C285 Cell_Resource DENOM_HSDPA_USERS_PER_CELLM1000C286 Cell_Resource SUM_HSUPA_USERS_IN_CELLM1000C287 Cell_Resource DENOM_HSUPA_USERS_PER_CELL

M1006C149 RRC ATT_RB_SETUP_HSDPAM1006C150 RRC SUCC_RB_SETUP_HSDPAM1006C192 RRC FAIL_RB_SETUP_HSDPA_NOREPLYM1006C193 RRC FAIL_RB_SETUP_HSDPA_UE



• 5. If high HSDPA Access Failure_BTS • Lack of UL channel resources (check CE resource utilisation using M5001 counters at BH)

• Too high SHO overhead – all branches must have enough CE capacity if UE is in SHO when HS-DSCH allocation is started

• RU10 brings new counters measure on the setup/success/failure for HSDPA MAC-d setup on NBAP Radio link Reconfiguration phase

• 6. HS-DSCH return channel setup fail due to Iub transport Breakdown the failure distribution (64,128,384,MAC-d) Evaluate RU10 UL rejection failure cause (M1022C131…C146) Evaluate number of reconfiguration failure due the transmission Check M1005C128 CANC_ADD_SRNC_TRAN_STP_FAIL Check RAB_STP_FAIL_XXX_IUB_AAL2, M1001C531-C533

0

200

400

600

800

1000

1200

1 14 27 40 53 66 79 92 105 118 131 144 157 170 183 196 209 222 235 248 261 274 287

0

5

10

15

20

25

30

SETUP_FAIL_BTS_HS_DSCH_BGR (Traffic)

AVE_AVAIL_PERC_POOL_CAPA_UL (Cellres)

M1005C241 L3Iub ATT_MACD_SETUP_FOR_HSDPAM1005C242 L3Iub SUCC_MACD_SETUP_FOR_HSDPAM1005C247 L3Iub FAIL_MACD_SETUP_HSDPA_NORESPM1005C248 L3Iub FAIL_MACD_SETUP_HSDPA_RNLM1005C249 L3Iub FAIL_MACD_SETUP_HSDPA_TRM1005C250 L3Iub FAIL_MACD_SETUP_HSDPA_PROTM1005C251 L3Iub FAIL_MACD_SETUP_HSDPA_MISC


Low HSDPA Retainability

• HSDPA Retainability Failure Cause Analysis can be done based on Traffic measurements (RNC_609a) and Packet Call measurements (RNC_920a)- optional measurement. Radio link failures should be analyzed.

System Program Report

RNC_920a/609a<X %

Check SCC Failure Rate – Radio, Iub, CE resource congestion

Check for RNC failures and use RNC logging if required

No Action Needed

HSPA packet call Radiolink failures

HSPA packet call failures - other

No

Yes

Yes

Yes

No

Check CQI distribution and Ecno distribution for coverage issue

Check HSDPA mobility parameter – Add/Drop window, SCC parameter

Service - RSRAN079


Low HSDPA Retainability (RNC_920a)

KPI RNC_920a :

• 100 -100 * sum ( PS_REL_RL_FAIL_HS_E_INT + PS_REL_RL_FAIL_HS_E_BGR + PS_REL_RL_FAIL_HS_D_INT + PS_REL_RL_FAIL_HS_D_BGR + PS_REL_OTH_FAIL_HS_E_INT + PS_REL_OTH_FAIL_HS_E_BGR + PS_REL_OTH_FAIL_HS_D_INT + PS_REL_OTH_FAIL_HS_D_BGR ) -------------------------------------------- sum ( PS_REL_RL_FAIL_HS_E_INT + PS_REL_RL_FAIL_HS_E_BGR + PS_REL_RL_FAIL_HS_D_INT + PS_REL_RL_FAIL_HS_D_BGR + PS_REL_OTH_FAIL_HS_E_INT + PS_REL_OTH_FAIL_HS_E_BGR + PS_REL_OTH_FAIL_HS_D_INT + PS_REL_OTH_FAIL_HS_D_BGR + PS_REL_NORM_HS_E_INT + PS_REL_NORM_HS_E_BGR + PS_REL_NORM_HS_D_INT + PS_REL_NORM_HS_D_BGR )

• RNC_609a:

• 100 * sum(REL_ALLO_NORM_HS_DSCH_INT + REL_ALLO_NORM_HS_DSCH_BGR) ----------------------------------------------------------------

sum( REL_ALLO_NORM_HS_DSCH_INT + REL_ALLO_NORM_HS_DSCH_BGR + REL_ALLO_OTH_FAIL_HSDSCH_INT + REL_ALLO_OTH_FAIL_HSDSCH_BGR + REL_ALLO_RL_FAIL_HS_DSCH_INT + REL_ALLO_RL_FAIL_HS_DSCH_BGR)



1. Identify root cause failure distribution and main contributor of low retainability

•

• 2. If high HSDPA Radio Link Failures (NRT) – dominant cause Compare to Cell Update ATT due to Radio link Failure (M1006C39) and Cell Update ATT

due to RLC Recoverable Error (M1006C40) Check Serving Cell Change failure rate (KPI RNC_733a) - high SCC failures lead to radio

link failure Check CQI distribution (M5000C8-M5000C39) or Ecno distribution for bad coverage issue

(M1007C38-M1007C47) Check HSDPA FMCS Mobility Control Parameter (handover or SCC too late) Check call re-establishment T315 timer due to radio link failure

Low HSDPA Retainability Service Level -> RSRAN079-> RNC_609a

Normal release


Low HSDPA Retainability

• 3. If high HSDPA Non- Radio Link Failures (NRL) UE responding with some failure message or not responding to some message but no

RL failure (timer expiry) Check RB reconfiguration, physical channel reconfiguration, NBAP RL reconfiguration

failure rate Required ICSU log for further troubleshooting ?



Low HSDPA SCC Success Ratio HSDPA SCC failure causes Analysis Flow Chart

• There seems not to be a relation with poor SCC success and HSDPA retainability. SCC success rate for HSDPA and HSUPA is not very accurate in cell level as denominator is incremented in the source cell (old serving cell) and numerator is incremented in the target cell (new serving cell).

Top N cells

SCC Fail BTS

RNC_733a < X %

SCC Fail ACSCC Fail Transmission

SCC Fail UESCC Fail Others

No action needed

Check CE resource usage at BH

scrambling code congestion BH

DL power congestion BH ?

Check AAL2 Iub resource congestion at BH

Check RB reconfiguration Failure rate

Check RNC internal transport resources (DMPG) – ICSU troubleshooting

No

Yes

YesYes Yes YesYes

No No NoNo

No

HSDPA SCC Success Ratio

SCC Fail Prevention timer

Check HSDPACellChangeMinInterval parameter

Check Maximum number of HSDPA users

No

No

Yes

Mobility & Handover –RSRAN033

RNC_733a:

100* sum(SCC_INTRA_BTS_SUCCESSFUL + SCC_INTER_BTS_SUCCESSFUL) / sum(SCC_STARTED_CPICH_ECNO + SCC_STARTED_UL_SIR_ERROR + SCC_STARTED_ACTIVE_SET_UPD + SCC_STARTED_OTHER_REASON)


Low HSDPA SCC Success Ratio

1. Determine HSDPA SCC success ratio (RNC_733a), SCC failure rate and failure cause distribution

•

• 2. Check target cells HSDPA Setup performance (M1002C401 – M1002C428) if source cells SCC failure rate is high • To find out which target cells are causing the SCC failure

3. If high SCC_FAILED_due_to_AC• Check target cells M1000C22 AVE_PTXTOT_CLASS_4 and M1000C20 AVE_PTXTOT_CLASS_3

if SCC failures due to the lack of DL power (SCC_Failed_due_to_AC)

• Check target cells M1002C521 or M1002C522 or M1000C144 (RAS06) – only when HSDPA static allocation

• Check target cells number of simultaneous active HSDPA users



Low HSDPA SCC Success Ratio • 4. If high SCC_FAILED_due_to_BTS

• Check target cells M1002C416/424 SETUP_FAIL_BTS_HS_DSCH_XXX

• Check target cells CE resource utilisation at BH using M5001 counters for lack of UL return channel resource

• Check NBAP Radio Link Reconfiguration Failure rate

• Check SHO overhead – use lower value for AdditionWindow (closer to 0 dB) in HSDPA FMCS than in the RT/NRT FMCS, to have smaller SHO area for HSDPA users.

• 5. If high SCC_FAILED_due_to_UE

• Check target cells M1002C415/423 SETUP_FAIL_UE_HS_DSCH_XXX

• Check RB reconfiguration Failure rate

• Require ICSU troubleshooting for UE types monitoring

6. If high SCC_FAILED_due_to_TRANS

• Check target cells of M1002C414 SETUP_FAIL_IUB_MAC_D_INT or M1002C422 SETUP_FAIL_IUB_MAC_D_BGR

• Evaluate number of reconfiguration failure due the transmission

• Check M1005C128 CANC_ADD_SRNC_TRAN_STP_FAIL

• Check M1001C531-C533 RAB_STP_FAIL_XXX_IUB_AAL2

7. If high SCC_FAILED_due_to_Others

• Check RNC internal transport resources usage (DMPG)

• Require ICSU troubleshooting



Low HSDPA Cell/User Throughput

HSDPA throughput limiting factors:

System Program -> RSRAN000 HSPA -> RSRAN051

HSPA -> RSRAN039

HSDPA Throughput Analysis Air interface

support from CQI distribution

HSDPA Throughput Available from Iub

BTS Power Availability for HSDPA

Cell Channelisation code Availability for HSDPA

RNC limiting factors: DSP, #simultaneous HSDPA users and throughput

Iu-PS capacity available or HSDPA

HSDPA UL Return channel limitation (CE)

HSDPA UL Return channel limitation (Iub)

HSDPA UL Return channel limitation (UL Interference)

Problem in

Air Interface

Iub

BTS

RNC

Iu-PS

BTS scheduler limitation (#simultaneous users per scheduler)



1. Check HSDPA active Throughput in the cell (RNC_722b/c) and Average throughput in the cell (RNC_606c) or with cell throughput in RNC/WBTS measurements (RNC_941a)

KPI RNC_941a : sum ( HS_DSCH_DATA_VOL * 8) /sum ( 1000 * PERIOD_DURATION)* 60 (kbps)

RNC_606c: sum(RECEIVED_HS_MACD_BITS - DISCARDED_HS_MACD_BITS) / sum(PERIOD_DURATION)*60 (kbps)

2. Calculate rough HSDPA User Throughput by dividing RNC_722b with average number of simultaneous HSDPA users (RNC_726a) or two new KPIs based on users in buffer where v2.1 is for user throughput <1.5Mbps


HSPA -> RSRAN039

Traffic - RSRAN077

ELLSS_3_0_IN_CHSDPA_USERELLSS_2_1_IN_CHSDPA_USERELLSS_1_2_IN_CHSDPA_USER

ELLSS_0_3_IN_CHSDPA_USERELLSS_2_0_IN_CHSDPA_USERELLSS_1_1_IN_CHSDPA_USER

ELLSS_0_2_IN_CHSDPA_USERELLSS_1_0_IN_CHSDPA_USERELLSS_0_1_IN_CHSDPA_USERELLS)S_3_0_IN_CHSDPA_USERELLSS_0_3_IN_CHSDPA_USER

ELLSS_2_1_IN_CHSDPA_USERCELLSRS_1_2_IN_(HSDPA_USE3

ELLS)S_2_0_IN_CHSDPA_USERELLSS_1_1_IN_CHSDPA_USERCELLSRS_0_2_IN_(HSDPA_USE2

ELLS)S_1_0_IN_CHSDPA_USERCELLSRS_0_1_IN_(HSDPA_USE

_PER_TTI_WITH_DATAHSDPA_BUFF

500TSHS_MACD_BIDISCARDED_-SS_MACD_BITRECEIVED_H

v3.0experienceuser End

2_PER_TTI_WITH_DATAHSDPA_BUFF

500TSHS_MACD_BIDISCARDED_-SS_MACD_BITRECEIVED_H

v2.1experienceuser End

M5002C21 Cell_Throughput_WBTS HS_TOTAL_DATA



• Below is comparison of all the throughput per user formulas as well as RNC_722b

•

Average HSDPA Throughput per User has increased a lot based on users in data buffer


Low HSDPA cell/user Throughput

3. Check RNC_706a Ave Reported CQI and CQI distribution (M5000C8-M5000C39) or Ecno distribution for bad coverage issue (M1007C38-M1007C47)

4. High CQI / Ecno but low HSDPA user throughput Check problem at core network or application server (FTP, HTTP) or in

measurement tools & PC settings Check any shortage on Iub user plane and CEs shortage due to DCH traffic is

too high Check if UL return channel is limiting due to interference

(PrxLoadMarginMaxDCH -> 0 dB) Check the if there is code blocking for HSDPA (set HSPDSCHMarginSF128 from

8-> 0) Check HSDPA power parameter setting (M1000C232-C235) & (M1000C236-C239) Check simultaneous HSDPA users in the Node B Scheduler (increase the

scheduler capacity from 16 users/BTS to 48 users/BTS (16/cell) Check HSDPA FMCS mobility parameters (lower window add for HSDPA than for

R99 to save capacity in target cell due to smaller SHO OH) Throughput limitation per user (throttled user) is active in Core?


HSPA -> RSRAN039


Low HSDPA Cell/Users Throughput

5. HSDPA power in BTS The counters tell the number of samples (TTI) per class when the actual used HS-PDSCH power (given as % value

from the max HS-PDSCH pwr) is within the limits defined for a class

This give hints whether low HSDPA throughput due to lack of HSDPA power (high RT/Rel99 NRT traffics in the

cell)

6. DMPG resource sharing causes the total throughput per user is not only limited by the # simultaneous users per cell and their activity but also the amount of simultaneous users per DMPG (per RNC sharing the total RNC throughput) and their activity

M5000C268 HSDPA_WBTS SAMPLE_HS_PDSCH_PWR_CLASS_01M5000C269 HSDPA_WBTS SAMPLE_HS_PDSCH_PWR_CLASS_02M5000C270 HSDPA_WBTS SAMPLE_HS_PDSCH_PWR_CLASS_03M5000C271 HSDPA_WBTS SAMPLE_HS_PDSCH_PWR_CLASS_04M5000C272 HSDPA_WBTS SAMPLE_HS_PDSCH_PWR_CLASS_05M5000C273 HSDPA_WBTS SAMPLE_HS_PDSCH_PWR_CLASS_06M5000C274 HSDPA_WBTS SAMPLE_HS_PDSCH_PWR_CLASS_07M5000C275 HSDPA_WBTS SAMPLE_HS_PDSCH_PWR_CLASS_08M5000C276 HSDPA_WBTS SAMPLE_HS_PDSCH_PWR_CLASS_09M5000C277 HSDPA_WBTS SAMPLE_HS_PDSCH_PWR_CLASS_10

Max HSDPA Throughput per RNC (62 x 7.2Mbps currently on RNC Throughput 450Mbps)

Sum ( #_users_with_data_in_buff_per_TTI / all_active_TTIs) x avg_#_HSDPA_users_in_RNC

HSDPA_NRTD_PEAK_CALLS


• HSUPA Accessibility Failure Cause Analysis can be done based on Traffic measurements (RNC_913a) and Packet call measurements (RNC_915c)- optional

Low HSUPA Accessibility

Low HSUPA accessibility

Check Number of simultaneous HSUPA users

(20/cell, 24/NodeB )

Check BH Channel element resource usage UL/DL

(BTS in state that no capacity available for EDCH)

HSUPA is not supported in SHO branch

Check BH Channel element resource usage UL/DL

Check RB reconfiguration failure rate

(Terminal problem)

Check AAL2 connections (not enough CID) or Signalling problems

No Action Needed

Too many HSUPA users reached

UL DCH selected due BTS HW

HSUPA fail due Not Acceptable Active Set

HSUPA Setup Fail BTS

HSUPA Setup Fail UE

HSUPA Setup Fail TRANS

No

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

No

No

No

No

No

Go for troubleshooting

( E.g. RNC internal failures)

HSUPA Setup Fail Other

Yes

Setup failures

Selection failures

Based on failure analysis from Traffic Measurement (M1002)



• RNC_915c :

• 100* sum(HS_E_REQ_HS_E_ALLO_STRE + HS_E_REQ_HS_E_ALLO_INT + HS_E_REQ_HS_E_ALLO_BGR) / sum(PS_ATT_HSDSCH_EDCH_STRE + PS_ATT_HSDSCH_EDCH_INT + PS_ATT_HSDSCH_EDCH_BGR - HS_E_REQ_HS_D_ALLO_STR_CELL - HS_E_REQ_HS_D_ALLO_BGR_CELL - HS_E_REQ_HS_D_ALLO_INT_CELL - HS_E_REQ_D_D_ALLO_STR_CELL - HS_E_REQ_D_D_ALLO_BGR_CELL - HS_E_REQ_D_D_ALLO_INT_CELL)

With RU10, there is new counters in packet call to identify packet call attempt to cells which are not HSPA enabled. New KPI (RNC_915c) gives better results in terms of HSUPA accessibility when networks mixed with HSPA and non-HSPA enabled cells. This avoids separate aggregation which required previously in RAS06.

RNC_914b does not include statistics from serving cell change mobility. Thus, the performance could be lower as well due to statistical calculation

• RNC_913a:

• 100 * sum ( ALLO_SUCCESS_EDCH_INT + ALLO_SUCCESS_EDCH_BGR ) --------------------------------------------- sum ( ALLO_SUCCESS_EDCH_INT + ALLO_SUCCESS_EDCH_BGR + EDCH_ALLO_CANC_NA_AS_BGR + EDCH_ALLO_CANC_NA_AS_INT + UL_DCH_SEL_MAX_HSUPA_USR_BGR

+ UL_DCH_SEL_MAX_HSUPA_USR_INT + UL_DCH_SEL_BTS_HW_INT + UL_DCH_SEL_BTS_HW_BGR + SETUP_FAIL_EDCH_BTS_BGR + SETUP_FAIL_EDCH_BTS_INT + SETUP_FAIL_EDCH_OTHER_BGR + SETUP_FAIL_EDCH_OTHER_INT + SETUP_FAIL_EDCH_TRANS_BGR + SETUP_FAIL_EDCH_TRANS_INT + SETUP_FAIL_EDCH_UE_BGR + SETUP_FAIL_EDCH_UE_INT )

System Program -> RSRAN000

Service Level-> RSRAN073

The number of DCH/DCH allocations after an HS-DCSH/E-DCH request for the backg/interactive traffic class due to the cell not supporting HSUPA and HSDPA



HSUPA Accessibility KPI is measured with RNC_913a (Traffic Measurement)

If HSDPA setup is failing also HSUPA setup will fail, but it could be also that only HSUPA will fail. The reasons are similar to HSDPA

RNC_956b E-DCH Setup FR due to BTS (RL reconfiguration failure to RNC)

RNC_1105b E-DCH Setup FR due to Transport (RL reconfiguration cancel from RNC)

RNC_1106b E-DCH Setup FR due to UE (RB reconfiguration failure from UE)

RNC_1104b E-DCH Setup FR due to Other Failures (RNC internal reason)

RNC_1103bE-DCH Allocation FR due to NA AS (due to non-acceptable E-DCH active set)

Also there could be too many HSUPA users (20/cell, 24/NodeB,In RU10:64 users/Node B)RNC_968b UL DCH Selected due to too many HSUPA users

RNC_969b DL DCH Selected due to the HSDPA power (updated when only HSDPA static power allocation used)

HSUPA setup failed due to BTS reports HSUPA cannot be allocatedRNC_957b E-DCH Not Selected due the BTS HW (BTS sent radio resource measurement report)

M1000C268-C270 – These counters measure the BTS HW limitation during HSUPA Calls





For static resource allocation the power could limitM1002C521 DL_DCH_SEL_HSDPA_POWER_INT

M1002C522 DL_DCH_SEL_HSDPA_POWER_BGR

M1002C602DL_DCH_SEL_HSDPA_POWER_STR

AC: (PtxTotal>PtxTargetHSDPA or PtxNC>PtxTargetHSDPA)

EDCH cannot be allocated in case HSUPA is not supported in SHO branch

M1002C519 EDCH_ALLO_CANC_NA_AS_INT

M1002C520 EDCH_ALLO_CANC_NA_AS_BGR

M1002C601EDCH_ALLO_CANC_NA_AS_STR




• HSUPA Retainability Failure Cause Analysis can be done based on Traffic measurements (RNC_919a) and Packet call measurements (RNC_921b)

Low HSUPA Retainability

RNC_919a / 921b <X %

Check SCC Failure Rate – Radio, Iub, CE resource congestion

Check for RNC failures??

No Action Needed

HSPA packet call Radiolink failures

HSPA packet call failures - other

No

Yes

Yes

Yes

No

Check CQI distribution and Ecno distribution for coverage issue

Check HSDPA mobility parameter – Add/Drop window, SCC parameter


Low HSUPA Retainability

RNC_921b (Packet Call Measurement)

• 100-100* sum(PS_REL_RL_FAIL_HS_E_STRE + PS_REL_RL_FAIL_HS_E_INT + PS_REL_RL_FAIL_HS_E_BGR + PS_REL_OTH_FAIL_HS_E_STRE + PS_REL_OTH_FAIL_HS_E_INT + PS_REL_OTH_FAIL_HS_E_BGR) / sum(PS_REL_RL_FAIL_HS_E_STRE + PS_REL_RL_FAIL_HS_E_INT + PS_REL_RL_FAIL_HS_E_BGR + PS_REL_OTH_FAIL_HS_E_STRE + PS_REL_OTH_FAIL_HS_E_INT + PS_REL_OTH_FAIL_HS_E_BGR + PS_REL_NORM_HS_E_STRE + PS_REL_NORM_HS_E_INT + PS_REL_NORM_HS_E_BGR + PS_SWI_HS_E_TO_D_D_STRE + PS_SWI_HS_E_TO_D_D_INT + PS_SWI_HS_E_TO_D_D_BGR)

RNC_919a (traffic measurement)

• 100 * sum ( REL_EDCH_NORM_INT + REL_EDCH_NORM_BGR + REL_EDCH_HSDSCH_SCC_INT + REL_EDCH_HSDSCH_SCC_BGR ) ---------------------------------------- sum ( REL_EDCH_NORM_INT + REL_EDCH_NORM_BGR + REL_EDCH_HSDSCH_SCC_INT + REL_EDCH_HSDSCH_SCC_BGR + REL_EDCH_RL_FAIL_INT + REL_EDCH_RL_FAIL_BGR + REL_EDCH_OTHER_FAIL_INT

+ REL_EDCH_OTHER_FAIL_BGR )

System Program - RSRAN000



The retainability of all successfully allocated E-DCH resources for NRT traffic is measured with KPI RNC_919a (Traffic Measurement)

There are several reasons for HSUPA release:RNC_1108a E-DCH Rel due to RL Failures

RNC_1109a E-DCH Rel due to Other Failures

RNC_1115a E-DCH Rel due to HS-DSCH serving cell change

(SCC released is included in both nominator/denominator of RNC_919a)

RL fail is incremented If:

– a radio link failure happens during HSDPA call (coverage issue)

– uplink RLC unrecoverable error happens (Cell Update by UE)

– RLC-entity in RNC reports RLC protocol reset

If RNC_919a < x%, refer also to step9 (low HSDPA retainability)

Low HSUPA RetainabilitySystem Program - RSRAN000



Low HSUPA SCC Success Ratio

HSUPA Serving Cell Success Ratio is measured with RNC_918b HSUPA Serving Cell Change are only done when the HSDPA Serving

Cell Change is needed (HSUPA SCC attempt is pegged along with HSDPA SCC attempt)

There are no failure counters for E-DCH serving cell change, but the failures are seen through HS-DSCH serving cell change counters

Check M1008C242 EDCH_DOWNG_DCH_IN_SCC - this counter incremented in new HS-DSCH serving cell when HS-DSCH serving cell change was successful, but uplink was downgraded from E-DCH to DCH

• RNC_918b:

100 * sum ( EDCH_SCC_INTRA_BTS_SUCCESS + EDCH_SCC_INTER_BTS_SUCCESS ) -------------------------------------------

sum ( EDCH_SCC_STARTED )

System Program – RSRAN000



Low HSUPA Throughput

Check Mininum, Maximum & Average HSUPA throughput from WBTS counter measurement (M5000C153)

Check average or data volume HSUPA throughput from Cell Throughput measurement with RNC_952csum(NRT_EDCH_UL_DATA_VOL + RT_E_DCH_UL_STREA_DATA) * 8 / sum(PERIOD_DURATION)*1000000*60

Check HSUPA throughput from M5002 Cell Throughput_WBTS and its throughput distributions in classes

Check HSUPA user throughput by dividing aboved with KPI RNC_1037a -Average number of simultaneous HSUPA users, during HSUPA usage

Traffic -> RSRAN070/077

HSPA -> RSRAN051

HSPA -> RSRAN039


Counter ID Measurement Counter nameM5002C41 Cell_Throughput_WBTS UE_HSUPA_TP03M5002C42 Cell_Throughput_WBTS UE_HSUPA_TP04M5002C43 Cell_Throughput_WBTS UE_HSUPA_TP05M5002C44 Cell_Throughput_WBTS UE_HSUPA_TP06M5002C45 Cell_Throughput_WBTS UE_HSUPA_TP07M5002C38 Cell_Throughput_WBTS UE_HSUPA_TP00M5002C39 Cell_Throughput_WBTS UE_HSUPA_TP01M5002C40 Cell_Throughput_WBTS UE_HSUPA_TP02M5002C46 Cell_Throughput_WBTS UE_HSUPA_TP08M5002C47 Cell_Throughput_WBTS UE_HSUPA_TP09M5002C48 Cell_Throughput_WBTS UE_HSUPA_TP10M5002C49 Cell_Throughput_WBTS UE_HSUPA_TP11M5002C2 Cell_Throughput_WBTS EDCH_DATA_SCELL_ULM5002C3 Cell_Throughput_WBTS EDCH_DATA_NSC_S_EDCH_UL

M5002C4 Cell_Throughput_WBTSEDCH_DATA_NSC_NS_EDCH_UL

Note: HSUPA cell throughput measurement is less accurate than HSDPA cell throughput due to counters updating across total measurement period and not in active data transfer period



Check CQI distribution (M5000C8-M5000C39) or Ecno distribution for bad coverage issue (M1007C38-M1007C47)

Check If low throughput due to high number of retransmission & failed retransmission (RNC_917a HSUPA MAC-es BLER)

Check KPI RNC_1165a/RNC_1166a for low HSUPA throughput due to Iub congestion (frame delay or frame loss)

In RU10, there is new counters to check on the Rise Over Thermal in Fractional load:L = 1 - (Pnoise/Ptotal), The fractional load is calculated in the normal scheduling operation. HSUPA throughput will be limited by high fractional load in the cells


HSPA -> RSRAN051

HSPA -> RSRAN039


M5000C245 FRACT_LOAD_DISTR_CLASS_00 - Ptotal>=Pnoise : (L = 0).

M5000C246 FRACT_LOAD_DISTR_CLASS_01 - Ptotal>=Pnoise : (0 < L <= 0.05)

M5000C247 FRACT_LOAD_DISTR_CLASS_02 - Ptotal>=Pnoise : (0.05 < L <= 0.1)


















M5000C265 FRACT_LOAD_DISTR_CLASS_20 - Ptotal>=Pnoise : (0.95 < L <= 1)



Check CQI distribution (M5000C8-M5000C39) or Ecno distribution for bad coverage issue (M1007C38-M1007C47)

Check If low throughput due to high number of retransmission & failed retransmission (RNC_917a HSUPA MAC-es BLER)

Check KPI RNC_1165a/RNC_1166a for low HSUPA throughput due to Iub congestion (frame delay or frame loss)

Check AVG_NON_HSDPA_PWR (M1000C138) & AVG_ACTIVE_NON_HSDPA_PWR to investigate whether high DCH power (DCH traffic) causes low HSUPA throughput

Others reasons with low HSUPA throughput• Check problem at core network or application server• Check HSPA FMCS / SCC mobility related parameters & performance

• Note: HSUPA throughput measurement is less accurate than HSDPA throughput due to counters updating across total measurement period


HSPA -> RSRAN051

HSPA -> RSRAN039



Low ISHO success rate


ISHO KPIs

2. Start from ISHO KPI in System Program (RSRAN000) in PLMN level -> RNC level-> Cell level and look at ISHO success rates

• RNC_300e (in RU10 RNC_300f)

• RNC_301c (in RU10 RNC_301d)


ISHO KPIs

2. Detailed ISHO performance can be studied in more detail for the worst cells.


ISHO KPIs

2. Detailed ISHO performance can be studied in more detail for worst cells- ISHO performance (separately for RT and NRT)

• Cell found ratio for RT tells how easily target cell is found (BSIC decoding need to be done in target GSM cell)

• BSIC decoding is not needed for NRT –> cell found ratio better

•RAS06 ED2.1 has ISHO NRT - Force Decode BSIC -> better ISHO succecss rate for NRT


ISHO KPIs

2. Detailed ISHO performance can be studied in more detail for worst cells- ISHO Handover per cause

• For each ISHO trigger (5) there are attempts & success KPIs

• Normally Main triggers are CPICH RSCP and CPICH EcNo

• ISHO for NRT is reselection which is done with cell change order (CCO)

• Note: there should be enough attempts to have reliable results (min 50 att per cell per day)

• ISHO triggers


2.Network level ISHO KPI example in mature single carrier 3G network with HSDPA

70.0

75.0

80.0

85.0

90.0

95.0

100.0

35 2

006

(28/

08/2

006)

37 2

006

(11/

09/2

006)

39 2

006

(25/

09/2

006)

41 2

006

(09/

10/2

006)

43 2

006

(23/

10/2

006)

45 2

006

(06/

11/2

006)

47 2

006

(20/

11/2

006)

49 2

006

(04/

12/2

006)

51 2

006

(18/

12/2

006)

01 2

007

(01/

01/2

007)

03 2

007

(15/

01/2

007)

05 2

007

(29/

01/2

007)

07 2

007

(12/

02/2

007)

09 2

007

(26/

02/2

007)

11 2

007

(12/

03/2

007)

13 2

007

(26/

03/2

007)

15 2

007

(09/

04/2

007)

17 2

007

(23/

04/2

007)

19 2

007

(07/

05/2

007)

21 2

007

(21/

05/2

007)

23 2

007

(04/

06/2

007)

25 2

007

(18/

06/2

007)

27 2

007

(02/

07/2

007)

29 2

007

(16/

07/2

007)

31 2

007

(30/

07/2

007)

0

500000

1000000

1500000

2000000

2500000

3000000

RNC_573a/ISHO cell found ratio, RT RNC_574a/ISHO cell found ratio, NRT RNC_300a/ISHO Success Rate RT

RNC_301a/ISHO Success Rate NRT RNC_298a/ISHO Attempts RT RNC_299a/ISHO Attempts NRT

Cell found ratio better

for NRT

ISHO success rate worse for

NRT


2.ISHO Signalling for RT

CNUE

Node B

RNC

RRC: Measurement Report

RRC: Measurement Control

NBAP: Radio Link Reconfiguration Prepare

NBAP: Radio Link Reconfiguration Ready

NBAP: Radio Link Reconfiguration Commit

RRC: Physical Channel Reconfiguration

RRC: Physical Channel Reconfiguration Complete

NBAP: Compressed Mode Command






RRC: Handover from UTRAN Command

GSM BSIC Identification

GSM RSSI Measurement

ISHO triggering (5 reasons are possible)

Initial Compressed Mode Configuration

RANAP: Relocation Required

RANAP: Relocation Command

RANAP: IU Release Command

RANAP: IU Release Complete


2.ISHO Signalling for NRT

UE Node B RNC



NBAP: Radio Link Reconfiguration Prepare

NBAP: Radio Link Reconfiguration Ready

NBAP: Radio Link Reconfiguration Commit

RRC: Physical Channel Reconfiguration

RRC: Physical Channel Reconfiguration Complete



RRC: Measurement Control GSM RSSI Measurement

ISHO triggering (5 reasons are possible)

Initial Compressed Mode Configuration

CN

RANAP: SRNS Context Request

RANAP: SRNS Context Response

RANAP: IU Release Command

RANAP: IU Release Complete

RRC: Cell Change Order from UTRAN

RANAP: SRNS Data Forward Command


2+ ISHO Cancellation in RU10

Counter ID Measurement Counter name PI name ReleaseM1010C214 Inter_System_Handover CANC_ISHO_REPL_NRT ISHO CANCEL DUE TO CELL REPLACEMENT FOR NRT RU10M1010C204 Inter_System_Handover CANC_ISHO_CPICH_RSCP_RT ISHO CANCEL DUE TO CPICH RSCP FOR RT RU10M1010C206 Inter_System_Handover CANC_ISHO_DL_DPCH_RT ISHO CANCEL DUE TO DL DPCH POWER FOR RT RU10M1010C217 Inter_System_Handover UNSUCC_IS_HHO_DR_AMR_RT UNSUCCESSFUL INTER SYSTEM HANDOVERS CAUSED BY DIRECTED RETRY FOR AMR RT RU10M1010C209 Inter_System_Handover CANC_ISHO_CPICH_ECNO_NRT ISHO CANCEL DUE TO CPICH ECNO FOR NRT RU10M1010C208 Inter_System_Handover CANC_ISHO_REPL_RT ISHO CANCEL DUE TO CELL REPLACEMENT FOR RT RU10M1010C207 Inter_System_Handover CANC_ISHO_ADD_RT ISHO CANCEL DUE TO CELL ADDITION FOR RT RU10M1010C210 Inter_System_Handover CANC_ISHO_CPICH_RSCP_NRT ISHO CANCEL DUE TO CPICH RSCP FOR NRT RU10M1010C211 Inter_System_Handover CANC_ISHO_TX_PWR_NRT ISHO CANCEL DUE TO UE TX POWER FOR NRT RU10M1010C213 Inter_System_Handover CANC_ISHO_ADD_NRT ISHO CANCEL DUE TO CELL ADDITION FOR NRT RU10M1010C205 Inter_System_Handover CANC_ISHO_TX_PWR_RT ISHO CANCEL DUE TO UE TX POWER FOR RT RU10M1010C203 Inter_System_Handover CANC_ISHO_CPICH_ECNO_RT ISHO CANCEL DUE TO CPICH ECNO FOR RT RU10M1010C212 Inter_System_Handover CANC_ISHO_DL_DPCH_NRT ISHO CANCEL DUE TO DL DPCH POWERFOR NRT RU10M1001C617 ServiceLevel RRC_CONN_STP_REJ_EMERG_CALL RRC SETUP REJECT DUE TO EMERGENCY CALL REDIRECTION RAS06M1001C803 ServiceLevel RRC_CONN_ACT_REL_ISHO RRC ACTIVE REL DUE TO ISHO RU10

• Related to RU10 ISHO cancellation feature new KPIs presented below, no experience from this yet– Compressed mode operation is cancelled here if one radio link becomes better

– Increases 3G coverage area, ISHO drop rate will be the same

– Decreases ISHO attempts due to CM cancel


3.ISHO analysis Flow Chart

ISHO Success Rate RT

Top N cells

RNC_300c < X %

No action needed

No

Missing ADJG or Bad Neighbour planning ?

Wrong 2G Ncell Parameter (BSIC) Or BSIC collision

No

YesYes

No

Too low ISHO triggering threshold or Strict ADJG minimum threshold (ADJGRxLevMinHO)

Non-optimumCompressed mode parameter set

Low ISHO Success ?

Low ISHO Measureme

ntsuccess ?

Missing or wrong 2G parameter in 2G MSC or SGSN (BCCH, LAC, CellID)

2G NcellCongestion

Missing neighbour list after re-selection after cell change order occured

Half Rate in 2G Ncell ????

Poor GSM Coverage

CM Start Not

Possible?

Yes

Check admission control rejection -> PrxTotal & PtxTotal

Yes

No


3. ISHO Failure Scenarios

• IS_COM_MOD_STA_NOT_POS (N)RT due to – AC rejects compressed mode request due to interference (DL or UL)

– Radio link (or physical channel) reconfiguration failure (BTS or UE reasons)

– ISHO is a parallel procedure (with radio link reconfiguration activity at same time, for example)

• Check busy hour data of PrxTotal , PtxTotal and M1000C22 AVE_PTXTOT_CLASS_4 and M1000C20 AVE_PTXTOT_CLASS_3 for AC rejection

0

10

20

30

40

50

60

70

2004

0906

2004

0907

2004

0908

2004

0909

2004

0910

2004

0911

2004

0912

2004

0913

IS_COM_MOD_STA_NOT_POS_RT

UE_PWR_RT

-110

-105

-100

-95

-90

-85

-80

-75

2004

0909

00

2004

0909

01

2004

0909

02

2004

0909

03

2004

0909

04

2004

0909

05

2004

0909

06

2004

0909

07

2004

0909

08

2004

0909

09

2004

0909

10

2004

0909

11

2004

0909

12

2004

0909

13

2004

0909

14

2004

0909

15

2004

0909

16

2004

0909

17

2004

0909

18

2004

0909

19

2004

0909

20

2004

0909

21

2004

0909

22

2004

0909

23

hour

dBm

Average_PrxTotal_excl_0 Average_PrxTotal_class_0 AVG_PRX_PWR



RNC

RRC: ”Measurement report”



RRC: ”Measurement report”(3,4,5)

RRC: ”Measurement Control”

Handover Command

When the UTRAN is not able to execute an Inter-System Handover the following counter is triggered:

UTRAN_NOT_ABLE_EXC_ISHHO_RT

The counter is triggered when the ISHO fails before the SRNC sends the handover command to the UE, in the same cell where the ISHO attempt has been updated:

• Relocation Preparation Failure or• TRelocPrep (def. 6s, from Relocation Required to

Relocation Command) expires.

The failure can take place for the following reasons:• Radio Resource congestion in the target cell• Radio Link setup/addition failure in the BTS (IFHO)• Failure during the Relocation preparation procedure

in the CN (for example ciphering parameter not set properly in 3G MSC, LAC mismatching in RNC/MSC)

• Failure during the Relocation resource allocation procedure in the target BSC

UTRAN FailureCounter

Relocation Procedure



RNC






HANDOVER FROM UTRAN

When the UE is not able to execute an Inter-System Handover the following counter is triggered:

UE_NOT_ABLE_EXC_ISHHO_(N)RT

The counter is triggered when the source RNC receives a failure message from the mobile with the failure cause “configuration unacceptable”.

The counter is triggered in the same cell where the ISHO attempt has been updated.

UE FailureCounter

CELL CHANGE ORDER FROM UTRAN

xHANDOVER FROM UTRAN FAILURE

CELL CHANGE ORDER FROM UTRAN FAILURE



RNC






Handover Command

When the RNC receives a failure message from the mobile and the cause is not “configuration unacceptable”, one of the following counter is triggered:UNSUCC_IS_HHO_UL_DCH_Q_(N)RTUNSUCC_IS_HHO_EU_TX_PWR_(N)RTUNSUCC_IS_HHO_DL_DPCH_PWR_(N)RTUNSUCC_IS_HHO_CPICH_RSCP_(N)RTUNSUCC_IS_HHO_CPICH_ECNO_(N)RT

The counter is triggered in the same cell where the ISHO attempt has been updated.

Reason for failure:• Physical channel failure (the UE is not able to

establish – in the target RAT – the phy. Channel indicated in the handover command)

• Protocol error• Inter-Rat protocol error• Unspecified

Handover FailureCell Change Failure

ISHO UnsuccessCounters

Cell Change Order (PS)

x



RNC






Handover Command

When the source RCC Connection drops during the ISHO, one of the following counter is triggered:CON_DRPS_IS_HHO_UL_DCH_Q_RTCON_DRPS_IS_HHO_EU_TX_PWR_RTCON_DRPS _IS _HHO_DL_DPCH_PWR_RTCON_DRPS _IS _HHO_CPICH_RSCP_RTCON_DRPS _IS _HHO_CPICH_ECNO_RT

For RT:TRelocOverall (def. 8s, from Relocation Command to Iu Release Command) expires.

RRC DropCounters IU Release Request

CN



RNC






When the source RCC Connection drops during the ISHO, one of the following counter is triggered:

CON_DRPS_IS_HHO_UL_DCH_Q_NRTCON_DRPS_IS_HHO_EU_TX_PWR_NRTCON_DRPS _IS _HHO_DL_DPCH_PWR_NRTCON_DRPS _IS _HHO_CPICH_RSCP_NRTCON_DRPS _IS _HHO_CPICH_ECNO_NRT

For NRT:RRC-TmrlRCC = T309+ InterRATCellReselTmrOffset expireswhere:

T309 parameter = 5 s (SIB1)InterRATCellReselTmrOffset is hidden parameter 3s

RRC DropCounters

IU Release RequestCN

Cell Change Order (PS)


3. Decision Algorithm

UE Tx Power (Event 6A)•Threshold:GsmUETxPwrThrXX •L3 filter: GsmUETxPwrFilterCoeff•Hysteresis margin: GsmUETxPwrTimeHyst•Data rate threshold HHOMAxAllowedBitrateUL

UL Quality•Timer:ULQualDetRepThreshold•Data rate threshold HHOMAxAllowedBitrateUL

DL DPCH power•Threshold: GsmDLTxPwrThrXX•Data rate threshold HHOMAxAllowedBitrateDL

(XX=AMR,CS,NrtPS,RtPS)

CPICH RSCP (Event 1F)•Thresholds:HHoRscpThreshold HHoRscpCancelL3 filter: HHoRscpFilterCoefficient•Timers:HHoRscpTimeHysteresisHHoRscpCancelTime

CPICH Ec/Io (Event 1F)•Thresholds:HHoEcNoThresholdHHoEcNoCancel•L3 filter:EcNofilterCoefficient•Timers:HHoEcNoTimeHysteresisHHoEcNoCancelTime

AdjgTxPwrMaxTCHAdjgRxLevMinHO (n)GsmMeasAveWindow

GsmMeasRepIntervalGsmNcellSearchPeriodGsmMinMeasIntervalGsmMaxMeasPeriod

Handover Execution

2G-to-3G back prevention

GsmMinHoInterval

2. GSM measurement reporting

4.ISHO Parameters

1. Triggering

2. GSM measuring

3. Decision


4.ISHO Optimum Parameters based on experience

• Lower triggering parameters have been used recently

• use Different FMCS sets for RT, NRT and HSDPA

• ISHO handover for NRT PS should be enabled (Cell change order)

Parameter Abbreviated Name Object Default values

Rec Values Internal value in RAC

Comments

CPICH Ec/No HHO Threshold, CPICH Ec/No HHO Cancel, CPICH RSCP HHO Threshold, CPICH RSCP HHO Cancel for NRT Services

HHoEcNoThreshold,HHoEcNoCancelHHoRscpThresholdHHoRscpCancel

FMCS NRT &FMCS HSDPA

-12 dB-9 dB-105 dBm-102 dBm

-16..-18 dB-12..-14 dB-115 dBm-110 dBm

same Lower values for for NRT services to increase the coverage area, valid for HSDPA also.Due the signalling delays at inter-system change caused by LU and RAU, and due to the low bit rate available in GPRS network without EDGE, it is beneficial to leave UMTS as late as possible

CPICH Ec/No HHO Threshold, CPICH Ec/No HHO Cancel, CPICH RSCP HHO Threshold, CPICH RSCP HHO Cancel for RT Services

HHoEcNoThreshold,HHoEcNoCancelHHoRscpThresholdHHoRscpCancel

FMCS RT -12 dB-9 dB-105 dBm-102 dBm

-14..-16 dB-10..-12 dB-108..-110 dBm-105..-108 dBm

same Lower values for RT to have more coverage.Absolute Isho number (and ISHO) drops will be decreased.

Parameter Abbreviated Name Object Default Recommended value

Internal Value in RAC

Handover of NRT PS Service to GSM GsmHandoverNrtPS RNC/HC&PC

No Yes 1


4.RAS06 ED2.1 example for NRT - Force Decode BSIC feature

ISHO NRT - Cell Found vs. Success Rate

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

01

.03

.20

09

02

.03

.20

09

03

.03

.20

09

04

.03

.20

09

05

.03

.20

09

06

.03

.20

09

07

.03

.20

09

08

.03

.20

09

09

.03

.20

09

10

.03

.20

09

11

.03

.20

09

12

.03

.20

09

13

.03

.20

09

14

.03

.20

09

15

.03

.20

09

16

.03

.20

09

ISHO NRT - Cell Found Ratio (574d ) ISHO NRT - Success Rate (301c) Cell Found x Success Rate

• ISHO success rate improved a lot


5. ISHO neighbour planning

• In RAS5.1 there are adjacency based ISHO counters (Autodef_ISHO counters: M1015C0-C1) to see ISHO attempts & ISHO success per adjacency.

• It is also possible to see ISHO to non-defined adjacency due to neighbour list combining (NCL) when UE is in SHO during ISHO process. This NCL combining is done by RNC.

• HO_ADJ_INTER_SYS_HHO_ATT

• HO_ADJ_INTER_SYS_HHO_COMPL

• These counters are updated when SRNC receives RANAP:IU RELEASE COMMAND from core network after successful Inter System HHO

• From these counters it is possible to calculate the ISHO share per adjacency (RNC_905a) & ISHO success rate per adjacency (RNC_902a), RSRAN045 report in Reporting Suite


5. Neighbour list Combination procedure- SHO/ISHO to undefined neighbour possible I

• Active Set may contain cells, which are not necessary adjacencies with each other. • The list of cells to be measured is send by the RNC in a MEASUREMENT

CONTROL message and is changed at every Active Set Update. The RNC then combines the Neighbour lists according to the following rules:

1. Active set cells are included2. Neighbour cells which are common to three active set cells are included3. Neighbours which are common to the controlling cell and a second active set

cell are included. (cell, other than the controlling cell, which has the highest CPICH Ec/Io)

4. Neighbour cells which are common to two active set cells are included 5. Neighbour cells which are defined for only one active set cell are included 6. Neighbours which are defined only for the second ranked cell are included7. Neighbours which are defined only for the third ranked cell are included

• If the total number of cells to be measured exceeds the maximum value of 32 during any step then handover control stops the Neighbour list generation


5. ISHO neighbour planning

• Example of RSRAN045 report (RAS06 reporting suite)– Low success rate for certain cell pairs, is it defined for a neighbour yet or

blocking in GSM or low coverage ?

)_____(______

)_____(*100905___

ATTHHOSYSINTERADJHOcellthefromadjaalloverSum

ATTHHOSYSINTERADJHOsumaRNCShareISHO

)_____(

)_____(*100902_____

ATTHHOSYSINTERADJHOsum

COMPLHHOSYSINTERADJHOsumaRNCADJGpersuccessISHO

Period start time Source WCEL ID Source WCEL adjacencies (#)Target LAC ID Target CELL ID ID Att HO share SR per adjacency12.01.2008 12382 7.0 9006 38583 63 20.72 33.3312.01.2008 11196 20.0 9006 7421 51 12.94 37.2512.01.2008 11196 20.0 9006 62065 85 21.57 40.0012.01.2008 11401 15.0 9006 62065 60 7.99 43.3312.01.2008 11196 20.0 9006 38583 139 35.28 58.9912.01.2008 11401 15.0 9006 38583 129 17.18 67.4412.01.2008 45220 12.0 9006 64208 70 32.71 80.0012.01.2008 11304 20.0 9007 145 57 12.10 80.7012.01.2008 11401 15.0 9006 7421 174 23.17 84.4812.01.2008 12382 7.0 9006 7421 149 49.01 85.9112.01.2008 11238 6.0 9006 35765 59 29.50 86.4412.01.2008 11690 16.0 9007 189 63 88.73 88.8912.01.2008 10017 25.0 9007 189 85 35.12 89.4112.01.2008 11401 15.0 9005 62876 86 11.45 89.5312.01.2008 11772 21.0 9005 757 58 9.63 89.66

Number of defined neighbours, max 32


6. GSM ISHO Analysis & Optimization

• Normally ISHO has not been activated towards 3G, instead Inter RAT cell reselection will happen to 3G in Idle mode

– bidirectional neighbour planning is used– Max number of the adjacent GSM cells = 32

31 if Inter-system handover feature is activated 30 if there also any of Common BCCH features is activated

• 2G ISHO can/will be used to decrease GSM load

• It has be noticed that when there are small 3G coverage 2G ISHO will happen successfully but then 3G ISHO will fail due to there is not enough time for CM + BSIC verification -> 2G ISHO needs good 3G coverage– ISHO cancellation in RU10 may cancel compressed mode in case one radio (if

in SHO) link is becoming better


Handover Triggering thresholds set in BSCHandover Triggering thresholds set in BSC

Inter-RAT measurements starts in case the RXLEV of the serving cell is above or

below the given threshold Qsearch_C, (threshold for Multi-RAT MS)

Inter-RAT measurements starts in case the RXLEV of the serving cell is above or

below the given threshold Qsearch_C, (threshold for Multi-RAT MS)

Handover decision is done in case ofload of the serving cell > load_Threshold and CPICH Ec/No (MET) > Min Ec/No

threshold

Handover decision is done in case ofload of the serving cell > load_Threshold and CPICH Ec/No (MET) > Min Ec/No

threshold

MS selects the target UTRAN cell based on measurement results

MS selects the target UTRAN cell based on measurement results

Handover command is send to MSCHandover command is send to MSC

Load threshold = 80% (default)Load reporting interval= 20 s (default)

Qsearch_C= never (default), this should be allways=7

Min EcNo Threshold (MET) = -15 dB

- FDD_MULTIRAP_REP: 2- Adjacent WCDMA RAN cell averaging window size [1-32], def=6

- Number of WCDMA RAN zero results [0-32], def=5- All adjacent WCDMA RAN cells averaged ([yes,no], def=NO):

(No means only the best three cells in the last sample.

- Reporting period increased by five seconds for each additional WCDMA RAN frequencies in the neighbour list.

- Minimum interval between unsuccessful ISHO attempts: 3 s

- A Penalty time applies which does not allow to initiatiate a handover

BACK to WCDMA during 30 s.

- In WCDMA, the parameter GsmMinHoInterval (default=10 s) determines the minimum interval between a successful inter-RAT handover from GSM to UTRAN and the following inter-RAT handover attempt back to GSM related to the same RRC connection.

6. GSM ISHO main Process & Parameters


6. GSM ISHO main Process & Parameters

• The inter-system handover works in connection with the intra-GSM handovers. For the situations when different handover criteria are met simultaneously, BSS has listed priorities for the handovers. In the first list the handover criteria are in priority order for TCH channel. This list has only 9 criteria with highest priority. The second one lists criteria for the SDCCH channel. The inter-system direct access is available in BSS11

1. Handover criteria for TCH2. Interference (uplink or downlink)3. Intra-segment inter-band due to downlink level (from higher to lower frequency

band)4. Uplink quality5. Downlink quality6. AMR unpacking (uplink level and also uplink unpacking quality triggers)7. Uplink level8. AMR unpacking (downlink level and also downlink unpacking quality triggers)9. Downlink level10. Inter-System Handover to WCDMA RAN


6. GSM ISHO parameter recommendations based on experience• Main Defaults can be used as such:

– ISHO enabling to UMTS is done with:• MIN TRAFFIC LOAD FOR SPEECH CALL

• THRESHOLD FOR MULTI-RAT MS

Parameter full Name Parameter Name BSS Release MO class Range def. value Rec. valueTHRESHOLD FOR MULTI-RAT MS QsearcC BSS11.5 HOC .0...15 15 7MIN TRAFFIC LOAD FOR SPEECH CALL utranHoThScTpdc BSS11.5 HOC .0…100 % 80% 0-5NUMBER OF MEASURED FDD CELLS fddMultiratRep BSS11.5 HOC .0...3 2MIN INTERVAL BETWEEN UNSUCC ISHO ATTEMPT minIntUnsuccIsho BSS11.5 HOC 0..255s, step1 s 3ADJACENT WCDMA RAN CELL AVERAGING WINDOW SIZE utranAveragingNumber BSS11.5 HOC 1..32, step1 6NUMBER OF WCDMA RAN ZERO RESULTS noOfZeroResUtran BSS11.5 HOC 0..32, step1 5ALL ADJACENT WCDMA RAN CELLS AVERAGED alladjacentCellsAveraged BSS11.5 HOC 0 (false), 1 (true) FALSEINTER-SYSTEM DIRECT ACCESS LOAD THRESHOLD interSystemDaLoadThr BSS11.5 HOC 0..100 %, step1 50%INTER-SYSTEM DIRECT ACCESS ENABLED interSystemDa BSS11.5 HOC 0 (false), 1(true) TRUETRIGGERING RATIO FOR WCDMA RAN CELL PENALTY FailMoveThreshold BSS11.5 HOC 0..100 %, step1WCDMA RAN CELL PENALTY wcdmaRanCellPenalty BSS11.5 HOC 0..255, step1 127MINIMUM CPICH EC/IO LEVEL minEcnoThreshold BSS11.5 ADJW .-24…0.5 dB -15 -8DIRECT ACCESS EC/IO THRESHOLD intSystemDaecioThr BSS11.5 ADJW .-24…0.5 dB -11.5Penalty Trigger Measurement Period TriggerMeasPeriod BSS11.5 BSC 2s..254s, step2s 128Early Sending Indication earlySendingIndication BSS11.5 BTS 0 (No), 1 (yes) 1FDD reporting threshold 2 FddRepThr2 BSS13 HOC .-115..-53 dBm -105


6. Reporting of 3G measurements and BSC decision

• MET tuning implies a compromise between blocked calls (GSM) and dropped calls(3G).

• MET should be higher than CPICH EcNo threshold for IS-HO 3G->GSM (default=–12 dB), in order to avoid ping-pongs and dropped calls.

At least 3dB difference between MET and CPICH EcNo threshold is suggested. Proposed MET value is –6..-8 dB

• Qsearch_C implies a compromise between the lifetime battery and the availability of the terminal to handover to 3G.

• it would be good to know the 3G coverage levels so that IS-HO can happen quickly.

• In the other side, UE may unnecessarily measure 3G cells when there is no conditions for ISHO.

• In later BSS release, 3G measurements will start according to the load conditions.

• Despite the lifetime battery, it would be good not to add obstacles to the terminal to move to 3G.

• Thus, proposed value in BSS is “always” (if 3G coverage exists).


6+. GSM ISHO in BSS13/RU10

• WCDMA neighbor cell reporting enhancement & Coverage based ISHO– The difference with Coverage based

ISHO for voice and Load & Quality criteria is that if there is no other GSM neighbour defined to the GSM cell then coverage based HO criteria is used to go to 3G, otherwise the existing load & quality criteria is used

– Feature is not used so far

Handover Triggering Thresholds set in BSCHandover Triggering Thresholds set in BSC

Inter-RAT measurements when: The RXLEVof the serving cell is above or below the given threshold Qsearch_C


Handover Decision is done in case of• Higher intra GERANHO failed but load of

serving cell < Load_Threshold• Load of the serving cell > Load_Threshold• and CPICH Ec/No> min Ec/No Threshold



MS reports best UTRAN cell based on measurement results• RSCP>= FDD_Reporting_Threshold2 (FRT2)



BSS20858:

WCDMAneighbour cell reporting enhancement

BSS20967:

Coverage based ISHOfor Voice

Handover Triggering Thresholds set in BSCHandover Triggering Thresholds set in BSC










BSS20858:

WCDMAneighbour cell reporting enhancement

BSS20967:

Coverage based ISHOfor Voice



• GSM to 3G Handover is also not triggered in previous release (before BSS13) due to the lower priority ISHO from GSM to 3G than intra GERAN HO criteria (interference, RxQual or RxLev). When one or several higher priority intra GERAN handover is exceeded but no handover is done due to bad GSM coverage, the evaluation of latter ISHO criteria is bypassed.



• The main reason of introducing FDD_Reporting_Threshold 2 in BSS13 is to prevent ISHO or IS-NCCR (Packet data transfer) from GSM to WCDMA FDD cells when the WCDMA FDD cells uplink quality is too week.

• Prior to BSS13, ISHO or IS-NCCR is only based on CPICH EcNo which provides only good estimation on downlink quality. As a result, UEs are in a situation where handover to WCDMA cells is failed due to uplink quality issue.

• This feature requires Rel5 dualmode UEs


7. Cell Reselection Parameters 3G -> 2G

First ranking of all the cells based on CPICH RSCP (WCDMA) and RSSI (GSM)

Rs = CPICH RSCP + Qhyst1Rn= Rxlev(n) - Qoffset1



Rn (GSM) > Rs (WCDMA)And

Rxlev (GSM) >QrxlevMin

Rn (GSM) > Rs (WCDMA)And

Rxlev (GSM) >QrxlevMin

YesNo

Cell re-selection to GSM

Cell re-selection to GSM

Neighbour WCDMA or GSM cell calculation with offset parameter

Serving WCDMA cell calculation, with

hysteresis parameter

UE starts GSM measurements if CPICH Ec/No < qQualMin + sSearchRAT

UE starts GSM measurements if CPICH Ec/No < qQualMin + sSearchRAT

SintraSearch

SinterSearch

SsearchRAT

CPICH EcNo

qQualMin

Second ranking only for WCDMA cells based on CPICH Ec/No

Rs = CPICH Ec/No + Qhyst2Rn=CPICH_Ec/No(n)-Qoffset2

Second ranking only for WCDMA cells based on CPICH Ec/No

Rs = CPICH Ec/No + Qhyst2Rn=CPICH_Ec/No(n)-Qoffset2 Cell re-selection to

WCDMA cell of highest R value

Cell re-selection to WCDMA cell of highest

R value


7. Cell Reselection Parameters 2G -> 3G

• Re-selection measurements are controlled by parameter threshold to search WCDMA RAN cells (QSRI)

• This parameter defines a threshold and also indicates whether these measurements are performed when RLA_C (a running average of received signal level) of the serving GSM cell is below or above the threshold

Check levels every 5s from serving GSM cell

and best 6 GSM neighbour cells

UE starts WCDMA measurements if Rxlev running average (RLA_C) is below or above

certain threshold:RLA_C Qsearch_I and Qsearch_P (GPRS)

UE starts WCDMA measurements if Rxlev running average (RLA_C) is below or above

certain threshold:RLA_C Qsearch_I and Qsearch_P (GPRS)

UE can select WCDMA cell if the level of the serving GSM and non-serving GSM cells has been

exceeded by certain offset for a period of 5 s:CPICH RSCP > RLA_C + FDD_Cell_Reselect_Offset

UE can select WCDMA cell if the level of the serving GSM and non-serving GSM cells has been

exceeded by certain offset for a period of 5 s:CPICH RSCP > RLA_C + FDD_Cell_Reselect_Offset

UE will re-select WCDMA cell in case it's quality is acceptable:

CPICH Ec/No Minimum_FDD_Threshold



Compare levels of all GSM cells

to WCDMAneighbour

Check quality of neighbour

WCDMA cells, no priorities between

WCDMA neighbours 05

.08:

Th

is m

ay t

ake

up

to

30s

In GSM the UE is usually set to measure the 3G neighbours all the time i.e. Qsearch_I and Qsearch_P are both set to 7


• As a general rule the value for FDD_Qmin parameter can be set to –8..-10 dB (i.e. for the case where the QqualMin +Ssearch_RAT = -14dB) to have enough hysteresis

7. Cell Reselection Parameters between 3G & 2G





The “rule” to set the FDD_Qmin value has not been possible to be fulfilled until the specification change (05.08 v8.18.0, 2003-8) has been implemented to the UEs – as below

QqualMin = -18dB

QqualMin + Ssearch_RAT = -14dB

FDD_Qmin >=-10

Camping in 3G Camping in 2G Camping in 3G

CPICH Ec/No

t

FDD_Qmin >= QqualMin + Ssearch_RAT

Fdd_Qmin mappingAif parameter 0 1 2 3 4 5 6 7Fdd_Qmin (old) [dB] -20 -19 -18 -17 -16 -15 -14 -13Fdd_Qmin (new) [dB] -20 -6 -18 -8 -16 -10 -14 -12


7. Cell Reselection Parameters between 3G & 2G

• However careful testing is needed to check the performance of different areas

• UEs must reselect correct cell in case of 3G outdoor to certain 2G – in these cases adjacency based parameter Adjqoffset1 can be used to prioritize certain 2G neighbor– Impacts the R-criteria as shown below






7. Cell reselection KPIs and Analysis

• RRC connection request amount for inter RAT cell reselection ratio to all RRC Connection request causes

• When Treselection is increased this KPI should decrease

• RRC connection request amount for registrations ratio to all RRC Connection request causes

• When Treselection is increased this KPI should decrease

TP_ATTRRC_CONN_SM1001C0

_ATTSELL_RE_SELINTR_RAT_C M1001C42

TP_ATTRRC_CONN_SM1001C0

ON_ATTSREGISTRATI M1001C46



• CSSR and especially the RRC Connection Setup and Access Complete must be monitored

• If the CSSRs or RRC Connection Setup and Access Complete decrease the Treselection value should be decreased

• RNC_94e: RRC Setup and Access Complete Ratio from network point of view

• RNC_565f: CSSR CS Voice (RAS06) or RNC_565e : CSSR CS Voice (RAS06)

• The RRC Connection Setup attempts should decrease after the parameter change – M1001C0 RRC_CONN_STP_ATT



• Following RRC Connection Setup failure causes should decrease as the amount of RRC Connection setup attempts is decreasing– M1001C3 RRC_CONN_STP_FAIL_AC

– M1001C4 RRC_CONN_STP_FAIL_BTS

– M1001C5 RRC_CONN_STP_FAIL_TRANS

– M1001C530 RRC_CONN_STP_FAIL_IUB_AAL2

• Above indicate saved resources and more detailed analysis can be done based on counters below– BTS CE : RAS05.1

– Iub : AAL2 Path Average Reserved Bandwidth % : RAS05

E_DLMAX_USED_C M5001C3 E_DLMAX_USED_C M5001C3

CE_UL MAX_USED_ M5001C4 CE_UL MAX_USED_ M5001C4E_DLMIN_USED_C M5001C5 E_DLMIN_USED_C M5001C5CE_UL MIN_USED_ M5001C6 CE_UL MIN_USED_ M5001C6

E_DLAVG_USED_C M5001C7 E_DLAVG_USED_C M5001C7

E_ULAVG_USED_C M5001C8 E_ULAVG_USED_C M5001C8

RATEGUAR_CELL_AAL2_PATH_ M550C0

SNBR_SAMPLE M550C7ATEVED_CELL_R SUM_RESERM550C1

100%


CLUSTER JBK09

0%

20%

40%

60%

80%

100%

<50% 50-70% 70-85% 85-100%

85-100% 1 1

70-85% 3 7 1 1

50-70% 12 10 9 7 6 8

<50% 41 39 47 50 51 48

6/ 19/ 2007 6/ 20/ 2007 6/ 21/ 2007 7/ 10/ 2007 7/ 11/ 2007 7/ 12/ 2007

BEFORE AFTER

Cluster JBK09

Count of % INTR_RAT_CELL_RESEL

Comparison Date

Grouping1

Cluster JBK09 Percentage Distribution after implementation:

☺Decreasing black and red colour as high percentage of Inter Rat Cell Reselection

☺Increasing green colour as low percentage of Inter Rat Cell Reselection

Decreasing

☺Before 25% of Cells having >50% of all RRC setups for inter RAT cell reselection

☺After 12% of cells having >50% of all RRC setups for Inter RAT cell reselection

7. Hysteresis Between 3G->2G and 2G->3G Cell Reselections – KPI Analysis ExampleHysteresis from 2dB -> 6dB


• For the the camping in indoor environment the set-up could be :

• Indoor GSM / Outdoor GSM (serving indoor)-> Indoor WCDMA / Outdoor WCDMA (serving indoor)

• Mobile station measuring WCDMA neighbor only when it is well inside the building using parameter Threshold to search WCDMA RAN Cells

• The defined set-up can be also used in outdoor environment to push the UEs to 3G as soon as possible from the 2G cell to the border 3G cell

7. Cell Reselection 3G & 2G


7+. Cell Reselection 3G & 2G in BSS13/RU10

• Currently used criterion for WCDMA cell reselection, i.e. CPICH Ec/No, is a good measure on the WCDMA downlink quality, but not on the uplink. If MS selects too weak WCDMA cell with low CPICH RSCP and fluctuating CPICH Ec/No, the end users service quality will be poor (call setup failure) and always it will return to GSM and a ping-pong effect between GSM and WCDMA is started.

• As a solution CPICH RSCP, which is a good measure on the WCDMA uplink quality telling about the present link budget margin, is added to the current cell reselection criterion. Taking care of both downlink and uplink requires triggering of cell reselection to WCDMA FDD if both CPICH Ec/No and RSCP exceed minimum requirements.

• With a new parameter on SI2quater, it is possible to have a complete evaluation of the quality of a certain cell => improved success rate of cell reselections towards WCDMA.

• The BSC manages the new FDD_RSCPmin and FDD_Qmin_Offset parameters and delivers them for dual-mode mobiles.



• Process flow



FDD_RSCP_Threshold>= Qrxlevmin +Pcompensation +SHCS_RAT

Qrxlevmin=-115 dBm

SHCS_RAT=10 dB

CPICH RSCP

FDD_RSCP_Threshold>= -100dBm

Qrxlevmin+Pcompensation +SHCS_RAT

t

Camping on 3G Camping on GSM Camping on 3G

FDD_RSCP_Threshold>= Qrxlevmin +Pcompensation +SHCS_RAT

Qrxlevmin=-115 dBm

SHCS_RAT=10 dB

CPICH RSCP

FDD_RSCP_Threshold>= -100dBm

Qrxlevmin+Pcompensation +SHCS_RAT

t

Camping on 3G Camping on GSM Camping on 3G

• With ping-pong issue with EcNo criterion, careful planning has to be taken when 3G -> 2G RSCP based cell reselection measurement is used (SHCS_RAT) together with FDD_RSCP threshold in 2G to 3G cell reselection.



• Some special scenarios for cell reselection parameters from GSM to 3G are presented below:

QserachI/QserachP= always

RSCP > RLA_C -24dB (Fdd_Qoffset)

EcNo > -12 dB (Fdd_Qmin + Fdd_Qmin_offset)

RSCP > -97dBm (Fdd_RSCP_threshold

HSPA area or High HSPA power area


RSCP > RLA_C-24dB (Fdd_Qoffset)




RSCP > RLA_C+ infinity (Fdd_Qoffset)

EcNo > -12dB (Fdd_Qmin + Fdd_Qmin_offset)

RSCP > -100dBm (Fdd_RSCP_threshold)

2G -> 3G

Outdoor 3G borderGeneral

2G -> 3G cell reselection


RSCP > RLA_C -24dB (Fdd_Qoffset)



HSPA area or High HSPA power area


RSCP > RLA_C-24dB (Fdd_Qoffset)




RSCP > RLA_C+ infinity (Fdd_Qoffset)

EcNo > -12dB (Fdd_Qmin + Fdd_Qmin_offset)

RSCP > -100dBm (Fdd_RSCP_threshold)

2G -> 3G

Outdoor 3G borderGeneral

2G -> 3G cell reselection

Soc Classification level 141 © Nokia Siemens Networks /

WCDMA Basic Parameters

• Brief description about following parameters:

• General BTS level

• Basic cell level

• Load control

• Power control

• Handover control

Basic bts parameters

Basic cell level parameters

Load control parameters

Power control parameters

Handover ontrol parameters


Thank U


Documents

3G RF Opt Process