1. RNO Wind
Part II

2. Part II - Content Retainability Compress Mode IRATHO
Drop cause relevance
Compress Mode
CM Time
IRATHO
Adjg Optimization
Failure analisys

3. Retainability

4. Retainability
Drop call (from 3G RNC side) can occur when UE is leaving the 3G layer (during inter-system HO) or in 3g layer.
It is not easy to find clear relationship between drop call in 3g layer and active set size or SHO success rate.
Considering WCELs with high permanence in “one cell in active state” (greater than 90% weighted value) no more than 50% suffer drop call value greater than 1% and increasing to higher value statistical data does not confirm the cause – effect relationship.
Same behaviour is revealed for SHO success rate KPI.
At the same way is not possible to find direct relationships between intersystem mobility failure procedure and high value of drop call.
The reason for that has to be seek in the masking effect of the counters involved either SHO or Active Set Size or in the IRATHO success rate KPIs
Drop call analisys have to be performed with a second level analisys taking into count that an averall improvement should come from ADJS and ADJG optimization

5. RAB & RRC Active Failures
RAB and RRC active failure reasons:
RNC Internal
BTS
UE (for user perspective)
Radio Interface
Iur Iu
RAB and RRC normal release:
RAB active complete
Pre-emption
SRNC Relocation
Unspecific error in CN (RAS05.1) UE
RNC
RAB Assignment Request (setup)
CORE
Radio Bearer Setup
RAB Assignment Response
Radio Bearer
Setup
Complete
RAB Assignment Request (release)
Iu Release Command
Iu Release Request

6. RAB & RRC Active Failures
By a RNO point of view the drop due to lack of radio resources are the most important.
Iu, Iur and RNC failure causes are neglected because the dimensioning should assure about it and out of RNO scope
Fail due to congestion has to be intended as caused by shortage of resources or not appropriate air interface.
In the following two KPIs to evaluate the drop cause that can be optimized:

7. RAB & RRC Active Failures
The retainability KPI does not take into account RRC-connections that move successfully through the cell, they only count drop ratio of RRCs that were released in the cell. In this way the drop KPI shows a bit too high values.
Generic Drop Call KPI does not take into count the following scenario:
To overcome this problem, new counters are implemented in RAS05.1 that are updated when the reference cell changes
In this context term “reference cell change” means the cell that e.g. M1006 RRC counters are updated and that is used as stop_bts when pmi_ticket
In Cell-FACH state the reference cell is the cell in which the UE is listening to the FACH channel
RRC Drop here causes RRC_CONN_ACT_FAIL_xx to be incremented and not RRC_CONN_ACT_COMP is incremented
Successful RRC Setup -> RRC_CONN_ACC_COMP is updated
M1001C443 RRC_CONN_OUT_REF_CELL - The number of RRC Connections that have left from the old reference cell
M1001C466 RRC_CONN_IN_REF_CELL - The number of RRC connections that enter a new reference cell

8. RAB & RRC Active Failures
Separating the numerator it is possible to have two separate KPIs for radio and BTS. This allows to differentiate the action required:
Radio
coverage plot , dominance must be verified
indication from UL/DL Load KPI (see PartI)
BTS
HW & CE resource must be checked using KPI for CE and codes
Start
DC due to congestion
Yes
RNP data anlisys
Load analisys
Radio?
Yes
BTS?
CE upgrade
HW check
End

9. Compress Mode

10. Compressed Mode Selection
CM is used to create idle periods (gaps) in the transmission during which ncell measurements on another
system can be made
Gaps can be created using single or double frame approach (Nokia supports both)
Because same data amount is sent in a shorter time => affects WCDMA coverage
Fast Power control information might be lost during the gap => higher Eb/No => affects WCDMA capacity
Compressed frames may be lost if power control is not set correctly => affects WCDMA quality
CM methods are Spreading Factor Halving and Higher Layer Scheduling
Measurement gap
Compressed
Mode
Power / Data Rate
Normal fra\\me
Normal frame
Normal frame
Compressed mode is not ideal from a “spectral efficiency point of view” only used when necessary
Spreading Factor Halving: like switching temporarily from ISDN64kbit to ISDN128kbit to transmit more data. Then use the time to carry out more measurements)

11. Compressed Mode Selection
Selection of the compressed mode method is performed in the following way:
AMR, RT PS or
CS data service
SF/2 used for both UL and DL
Transmission Gap Pattern:
Single frame: 7 slot gap,
variable # of normal frames
NRT PS data service
Higher layer scheduling is
Used for both UL and DL
# of normal frames
Double frame: 7 slot gap,
Selection between HLS ½ and
HLS ¾

12. CM Time
The following counters are available for the CM procedure monitoring
M1002C437 ALLO DURA FOR COM MODE UL USING SF/2 METHOD IN SRNC / M1002C433 ALLO FOR COM MODE UL USING SF/2 METHOD IN SRNC
M1002C438 ALLO DURA FOR COM MODE DL USING SF/2 METHOD IN SRNC / M1002C434 ALLO FOR COM MODE DL USING SF/2 METHOD IN SRNC
M1002C440 ALLO DURA FOR COM MODE DL USING HLS METHOD IN SRNC / M1002C436 ALLO FOR COM MODE DL USING HLS METHOD IN SRNC
M1002C439 ALLO DURA FOR COM MODE UL USING HLS METHOD IN SRNC / M1002C435 ALLO FOR COM MODE UL USING HLS METHOD IN SRNC
Dividing the duration by the respective allocation is possible to have an estimation of the CM Time
The approaching of the limit GSMMeasRepInterval * GSMMaxMeasPeriod
can be considered as an indication for the tunig of the related parameters
Time for cell search and for CM can be tuned as well

13. CM Time RNC GSMRepInterval * GSMNcellSearchPeriod
After HO triggering condition is fulfilled a RRC message ”Measurement Control” is sent to UE
containing details of the measurement that the UE must execute.
RRC: ”Measurement control ” message (GSM RSSI measurements)
RNC UE
The neighbour cell search is regulated by the GSMNcellSearchPeriod period parameter. ISHO is not allowed until the are enough measurement reports given by this parameter (O means that only 1 measurement result is enough for decision making)
Duration of the cell search period is calculated by:
GSMRepInterval * GSMNcellSearchPeriod

14. CM Time GSMMeasAveWindow RNC GsmMeasRepInterval
Upon reception of the measurements reported by the UE, RNC applies a sliding averaging window to theRXLEV measurements. The averaged levels are used as input to the IS-HO decision algorithm.
GSMMeasAveWindow
is Measurement Averaging Window size, sliding window is used
RNC UE
The first measurement report
has info from the best GSM cell:
BCCH freq & RSSI, no filtering
used in UE
RRC: ”Measurement report”
GsmMeasRepInterval
is the interval between measurement reports, which are sent to BTS
RRC: ”Measurement report”
RXLEV measurements are reported through
”Measurement report” messages

15. CM Time WBTS RNC GSMMinMeasInterval
In case of an unsuccessful IS-HO attempt, the network will deactivate compressed mode for a time period given by GSMMinMeasInterval
WBTS
RNC
NBAP: Compressed Mode Command
GSMMinMeasInterval
This is Minimum Measurement Interval, wait time when the following CM starts.
NBAP: Compressed Mode Command
If the RNC is not able to execute an inter-system Handover, it shall stop the inter-system measurements after the UE has sent the predefined number of measurement reports to the RNC, given by GSMMaxMeasPeriod
The Maximum allowed duration of the inter-system measurement is calculated:
GSMMeasRepInterval * GSMMaxMeasPeriod [ es:0.5*20 =10s,]

16. CM Time The CM time should never approach the max limit stated by
Start
The CM time should never approach the max limit stated by
GSMMeasRepInterval * GSMMaxMeasPeriod
The best cndition is to perform the IS with the minimum time
GSMRepInterval * GSMNcellSearchPeriod
without failure.
In the other cases ADJG optimzation or tunig of parameters are required
Yes
CM Time approach max?
CM Time approach min?
System stable
Yes
Verify
# No Cell Found
Yes
Yes
High # No Cell Found?
New ADJG
availale?
Add ADJG
CM tuning
1E/1F tuning

17. IRATHO

18. IRATHO
As M1013 described in PartI, M1015 return statistic for intesystem HO. The filtering criteria can be replicated with the exception of ping-pong
Filtering criteria:
Major
- High number of failures for a defined out-going adjg (failure ADJG)
- high number of fail for a defined source (failure WCEL)
Minor
- very low number of attempt with failure (low used adjg)
- zero number of attempt for declared adjs– stabilized value (no adjg)
- high number of attempts for an out-going adjs (unbalanced ADJG)
out-going condition is sufficient
- high number of attempts for a defined source (unbalanced WCEL)
Same procedures can be applied to the case considering that the event related are 1E and 1F

19. 1E/1F Events for CPICH Ec/No and RSCP
HHoEcNo(RSCP)Threshold
determines the absolute CPICH Ec/No threshold which is used by the UE to trigger the reporting event 1F. When the measured CPICH Ec/No of all active set cells has become worse than or equal to the threshold in question, the RNC starts inter-frequency or inter-RAT (GSM) measurements in compressed mode for the purpose of hard handover.
HHoEcNo(RSCP)Cancel
Defines the threshold of Ec/No(RSCP) that must be exceeded by a measurement of an active set cell to be canceled the event 1F related
Cell 1
Cell 2
e.g. P-CPICH Ec/No
Cell 3 1F 1E
time
HHoEcNo(RSCP)CancelTime
determines the time period during which the CPICH RSCP of the active set cell must stay better than the threshold HHoRscpCancel before the UE can trigger the reporting event 1E.
HHoEcNo(RSCP)TimeHysteresis
determines the time period during which the CPICH Ec/No of the active set cell must stay worse than the threshold HHoEcNoThreshold before the UE can trigger the reporting event 1F.

20. IRATHO – Triggering reason
1. Low measured absolute
CPICH Ec/No, event 1E/1F
FMCG: GSMcauseCPICHEcNo
2 . Low measured absolute
CPICH RSCP, events 1E/1F
FMCG: GSMcauseCPICHrscp
Triggering reason gives
an indication
3. UE Tx power approaches its maximum allowed power, event 6A/6D
FMCG: GSMcauseTxPwrUL
4. DL DPCH approaches its
maximum allowed power
FMCG: GSMcauseTxPwrDL
6 . Others
- Load and Service based HO
- IMSI based HO
- Emergency ISHO
5. Quality deterioration report
from UL outer loop PC
FMCG: GSMcauseUplinkQuality
GSMcauseX
These parameters indicates whether a handover to GSM caused by low measured absolute CPICH Ec/No of the serving cell is enabled (1)

21. IRATHO – Triggering reason
It’s important to know which is the most frequent triggering reason:
It’s possible to diffentiate between quality and coverage reasons and understand the
network limiting factors:
CPICH coverage
Pilot pollution
UL/DL Service coverage
In actual case is possible to dsciminate between low CPICH coverage triggered by high# RSCP
attempts or probable pilot pollution triggered by high # Ec/No attempts
A KPI that gives reason for that is

22. IRATHO – Triggering reason
Enabling all the causes a screaning on the network is returned individuating the limiting factor and the required action.
Start
Yes
High # Ec/No?
DL Qual limiting
DL interference/ Pollution should be evaluated DL
Yes
High # RSCP?
DL level limiting
CPICH power analisys/ new site required
This condition should be the dominannt one without associated failure
Yes
High # UE
Tx pwr?
New site required or new
Parametrization for IRATHO
UL level limiting UL
Yes
Load analisys and UL interference evaluation
High # UL Qual?
UL qual limiting
End
Yes
High # DL
DPCH?
Service limiting
New planning for service is required

23. IRATHO - Failure Failure can happen at different point:CN UE
Node B
RNC
RRC: Measurement Control
Failure can happen at different point:
Before decision
- Before CM
- During CM
- Measuring GSM cell
After decision
- Drop
Utran and ue have to treated as particular case
ISHO triggering (5 reasons are possible)
RRC: Measurement Report
NBAP: Radio Link Reconfiguration Prepare
NBAP: Radio Link Reconfiguration Ready
Initial Compressed Mode Configuration
NBAP: Radio Link Reconfiguration Commit
RRC: Physical Channel Reconfiguration
RRC: Physical Channel Reconfiguration Complete
NBAP: Compressed Mode Command
RRC: Measurement Control
GSM RSSI Measurement
RRC: Measurement Report
RRC: Cell Change Order from UTRAN
RANAP: SRNS Context Request
RANAP: SRNS Context Response
RANAP: SRNS Data Forward Command
RANAP: IU Release Command
RANAP: IU Release Complete

24. Admission Control check for CM
CM not possible
RNC UE
RRC: Measurement Report (3,4,5)
RRC: Measurement Control
BTS
Admission Control check for CM
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: Measurement Report
BSIC verification phase for target cell
RX Level measurement phase for
all ISHO neighbours
AC is responsible for checkiing if CM is possiblle
If CM fails one of the following mus be checked:
Not enough resources – AC reject CM.
Evaluate interference
Expand capacity
(see PartI)
The following KPI gives an indication of the number of CM procedure not started
Considering that M1010C2 (INTER SYST COM MOD STA NOT POS FOR RT) is updated if it is not possible to start inter-system compressed mode measurement due to radio resource congestion, BTS- or UE-related reasons to have a better insight on radio congestion it could be better to use, e.g. for UL the M1002C361 REQ FOR COM MODE UL REJECT TO INT SYST HHO IN SRNC and the M1002C357 REQ FOR COM MODE UL TO INT SYST HHO IN SRNC and use the following :
M1002C361/M1002C357

25. NO Cell Found … measurement fail … measurement not fail No Cell Found
Compressed
Mode start
No Cell Found
Counters
HHO Attempt
NO Cell Found means:
there is no suitable gsm target cell in terms of RX Level OR
the target gsm is suitable but its BSIC verification fails
AND
the maximum number of measurement reported are received
maximum measurement interval is not expired
… measurement not fail
The following KPI gives an indication of the number of GSM cell not found
Missing ADJG could be the reason or a dedicated parameter tuning for the 1F event. The KPI can be madified taling care of the WO_CMOD events

26. NO Cell Found Start High # NO Cell? End Yes Yes New site required
GSMCause=Ec/Nol?
Pollution evaluation
Reduce “Cancel”
Increase “Time hysteresis”
Verify
ADJG
Good GSM coverage in the far field?
ADJG
Addition?
Coverage anlisys
Good GSM coverage in the near field?
Yes
Yes
Reduce
“thershold”
End

27. DROP & UNSUCCESS IRATHO
Optimization for unsuccess is not possible because the reason are:
- physical channel failure (the UE is not able to establish the phy.
- Protocol error
- Inter-Rat protocol error
- Unspecified
Drop are related to drop call occurred during the procedure
UTRAN Failure
Counter
UE Failure
Counter
ISHO Unsuccess
Counters
HHO Attempt
Counters
ISHO Success
Counters
In this case the optimization is required and pass through the evaluate of GSM and 3G plot coverage. Optimize If necessary number of ADJG or NWP parameters otherwise tune RNW parameters.
Thresholds can be relaxed to favourite an early exit from 3G layer
RRC Drop
Counters

28. 3G –> 2G Unbalancing
This topic present the inherent problem due to the fact that the 2G layer is not involved in the analisys.
Few consideration can be performed under some assumption:
The following KPIs used over a cluster for CS voice service gives the percentage of the CM started over all the RAB, giving an idea of the attempted mobility procedure requested for a cluster where the 3G coverage should be assured
Better to use completes: failures, normal & SRNC reloc on denominator and use the KPI inside the 3G cluster or difining a polygon where 3G service is required
Once Correlated with voice drop due to radio link failure and rrc drop during ISHO, the KPI can help operator in understand the ISHO strategy. Similar KPI is possible for PS
Threshold to shrink the HO area or inhibit the procedure has to be setted

29. How to use Nokia core and secondary colors
Nokia secondary color palette (secondary blue, secondary neutrals, secondary brights) can only be used in charts and shapes, in addition to core colors.
Nokia blue
Nokia green
Nokia secondary blue
Nokia secondary colors for charts & shapes
R 000
G 051
B 204
R 068
G 165
B 028
R 175
G 212
B 240
R 235
G 233
B 216
R 191
G 215
B 218
R 230
G 192
B 031
R 175
G 148
B 023
R 206
G 150
B 032