Soc Classification level
1 © Nokia Siemens Networks DNO Optimization Processes / JC Ejarque / 15.09.09
Optimization Processes- veeresh 3G Performance Engineer
Soc Classification level
2 © Nokia Siemens Networks DNO Optimization Processes / JC Ejarque / 15.09.09
CSSR VOICE ACCESSIBLITY OPTIMIZATION—COUNTERS
3 © Nokia Siemens Networks DNO Optimization Processes / JC Ejarque
Perform data analysis and assessment
1. Assess weekly average PLMN KPI performance to identify KPIs below targets
• Start from bigger picture assessment (PLNM -> RNC -> Cluster -> WCEL )
• Weekly average will smooth the performance and gives better accuracy of performance assessment as daily performance varies a lot especially in unloaded network
• 2. Assess network performance at RNC/Area level to check if bad performance happens across network or only particular RNC/Area
• Compare different RNC/Regions performance
• 3. Apply drill down approach to assess bad performing KPIs in WCEL level
• Identify the failure call phases
• Categorizing failure ratio or distribution of each counters (radio, AC, transmission, BTS, RNC)
• Identify main cause of underperforming KPIs
• 4. Prioritize analysis
• Filter using high number of failures or high number failure ratio (weighting)
• Identify top 50 worst cells
4 © Nokia Siemens Networks DNO Optimization Processes / JC Ejarque
Perform data analysis and assessment
Using smart 3G RAN Reports,
Weekly KPI
( PLMN)
< X %
No action
needed
No
Yes
Yes
No
System Program (PLMN)
Weekly KPI
(RNC)
< X % ?
System Program (RNC)
Daily KPI
(WCEL)
< X%
Identify Call failure
phases of bad
performing KPIs,
for example
CSSR
Identify failures root-
causes and failure
distribution of bad
KPIs
Identify Top50 Worst
Cells based on
highest number of
root causes failures
System Program (WCEL) Others 3G RAN Reports
Others 3G RAN Reports Yes
Mataching failure
distribution into
network topology
System Program (WCEL)
Solution Proposal
Mapinfo
5 © Nokia Siemens Networks DNO Optimization Processes / JC Ejarque
CSSR CS/PS Analysis Failure counters
6 © Nokia Siemens Networks DNO Optimization Processes / JC Ejarque
CSSR definition
7 © Nokia Siemens Networks DNO Optimization Processes / JC Ejarque
Low in CSSR?
Identify call setup failure phases Call Setup Phases
CSSR affected if any of the followings take
place.
1. RRC Conn. Setup Fail
2. RRC Conn. Access Fail
3. RAB Setup Fail
4. RAB Setup Access Fail
Call Setup Phase
RRC
Conn. Req
RRC
Conn. Setup
RRC
Conn. Acc RRC
Conn. Act RAB Setup RAB Drop
Call Setup Success Call Drop
Connected
8 © Nokia Siemens Networks DNO Optimization Processes / JC Ejarque
Low in CSSR?
RRC/RAB Setup & Access Analysis Process Flow Chart
Sites OK ?
Cell and Neighbour Cells availabilityAlarms/Tickets
Setup /Access
Yes
Setup /Access
Setup Failure Cause?
Capacity Optimisation
BTS/TRANS/FROZBS
UL/DL Interference (DL codes)
AC
TroubleshootingRNC
RF Optimisation
Top (N) RRC Setup and Access failures
Top (N) RAB Setup and Access failures
Coverage/ Interference
setup
setup
Interference
Coverage
3G cell at inter-RNC border ?
SRNS Relocation troubleshooting
Yes
NO
Access
Access
Sites OK ?
Cell and Neighbour Cells availabilityAlarms/Tickets
Setup /Access
Yes
Setup /Access
Setup Failure Cause?
Capacity Optimisation
BTS/TRANS/FROZBS
UL/DL Interference (DL codes)
AC
TroubleshootingRNC
RF Optimisation
Top (N) RRC Setup and Access failures
Top (N) RAB Setup and Access failures
Coverage/ Interference
setup
setup
Interference
Coverage
3G cell at inter-RNC border ?
SRNS Relocation troubleshooting
Yes
NO
Access
Access
9 © Nokia Siemens Networks DNO Optimization Processes / JC Ejarque
RRC Part Performance – Signaling and Trigger points positive
[RACH] RRC:RRC Connection
Request
UE Node B RNC
ALCAP:ERQ
NBAP: RL Setup Request
[DCH] RRC: RRC Connection Setup Complete
L1 Synchronisation
Start
TX/RX
Start TX/RX
[FACH] RRC: RRC Connection
Setup
NBAP: RL Setup
Response
AC to check to accept or reject RRC
Connection Request
ALCAP:ECF
NBAP: Synchronisation Indication
RRC Connection Setup phase
RRC Connection Access phase
RRC Connection Active
phase
Allocation of UTRAN
resources
Waiting for UE reply
RRC active complete Pre-Emption
SRNS Relocation
drop
M1001C0
M1001C1
M1001C8
10 © Nokia Siemens Networks DNO Optimization Processes / JC Ejarque
RRC Part Connection Setup & Access and Active negative
BTS UE RNC CN
RRC: RRC connection Request
RRC: RRC connection Setup
RRC SETUP phase
(Resource Reservation in RNC, BTS,
Transport)
RRC ACCESS phase
(RNC waits for Reply from UE)
RRC: RRC connection Setup Complete
RR
C S
etu
p tim
e
RRC: Initial Direct Transfer
RANAP: Initial UE Message
RANAP: Iu Release Command
UE-CN Signalling
(E.g. RAB Establishment and Release)
RRC: RRC connection Release
RRC: RRC connection Release Complete
Release RRC resources in RNC, BTS,
Transport
RRC ACTIVE phase
RRC ACCESS fails if the UE does not reply to RRC: RRC
CONNECTION SETUP message with the RRC: RRC CONNECTION
SETUP COMPLETE message in given time, if the BTS reports a radio
link synchronisation failure or in an RNC internal failure occurs
RRC SETUP fails if some of the needed resources (RNC, BTS, AIR,
Transport) are not available. When an RRC setup failure occurs the
RNC sends an RRC: RRC CONNECTION REJECT message to UE
RRC ACTIVE fails when an interface related (Iu, Iur , Iub, or Radio) or
RNC internal failure occurs, and the failure causes the release of the
RRC Connection. When an RRC active failure occurs, the RRC send a
RANAP: IU RELEASE REQUEST to all involved CNs and waits for
RANAP: IU RELEASE COMMAND message (s)
RRC ACTIVE release cause can be either ISHO,
IFHO, SRSN relocation or pre-emption
11 © Nokia Siemens Networks
RRC SETUP PHASE --
DNO Optimization Processes / JC Ejarque
12 © Nokia Siemens Networks
RAB SETUP PHASE
DNO Optimization Processes / JC Ejarque
13 © Nokia Siemens Networks RANOP2_M1/January 2011
UE RRC: Connection Request
RRC: RRC Connection Request Setup
RRC: RRC Connection Completed
RRC: Initial Direct Transfer cm service request
RANAP: Initial UE Message
DIRECT TRANSFER (Call Proceeding)
RANAP: RAB Assignment
Request
RRC: Radio Bearer Set-up
RRC: Radio Bearer Setup Complete
RANAP: RAB Assignment Response DIRECT TRANSFER (Alerting)
BTS RNC CN
DIRECT TRANSFER (Connect)
DIRECT TRANSFER (Connect Acknowledge)
RAB Connection Access phase RNC waits reply from UE
Call Set-
up
Success
Rate Call Set-
up Time
Definition of Call Set-Up Success Rate (CSSR)
RRC Connection Access phase RNC waits reply from UE
RRC Connection Setup phase Resource Reservation in RNC, BTS, Transmission
RAB Connection Setup phase Resource Reservation in RNC, BTS, Transmission
For Internal Use Only
14 © Nokia Siemens Networks
Failure analysis for low CSSR/SSSR cells
RRC, RAB Setup, PS
Setup Failure due AC
RRC, RAB, HSPA Setup
Performance KPI/counters
Follow-Up Yes
No
Air Interface
RRC, RAB Setup, PS
Setup Failure due
BTS
Yes
No
BTS
RRC, RAB Setup, PS
Setup Failure due Iub
Yes
No
Iub
RRC, RAB Setup, PS Setup
Failure due RNC, DMCU
Yes RNC
RRC, RAB Setup failure due
to Frozen BTS
No
Yes High Traffic Event
RANOP2 - M2/January 2011
For Internal Use Only
15 © Nokia Siemens Networks RANOP2 - M2/January 2011
Starting criteria for setup failure analysis
RRC or RAB setup failures could be due issues related to
• Coverage or interference
• Inter RNC problem
• Capacity
• Configuration & SW issues
Capacity issues could results to the RRC/RAB setup failures related to
• BTS for Channel Element (WSP & FSM) capacity issues
• TRANS for Iub capacity issues
• AC for radio capacity issues (UL Load, DL Load and DL spreading codes)
16 © Nokia Siemens Networks DNO Optimization Processes / JC Ejarque
Low in CSSR: Failure Counters-I RRC Conn Setup & Access Analysis
RRC_CONN_STP_FAIL_AC
Check UL Interference, DL Power & Code occupancy if there is need to upgrade radio
capacity
Check over shooting, cell availability of own and target site , Special Events High
Traffic , Missing Neighbour
Check the alarms for the serving Node B and Neighboring sites in order to identify any
hardware faults
RRC_CONN_STP_FAIL_BTS
Evaluate NBAP counters (radio link reconf. Failures) and KPIs for troubleshooting BTS
resources
Check BTS configuration in terms of CE allocation –
Check the Available CE in comparison with CE utilization( Module might be down )
Expand the Capacity or decrease the traffic offered to the site until the problem is
solved
In case BTS is not responding delete and re-create COCO
Upgrade the Module to FSME :MAX CE element
17 © Nokia Siemens Networks
Low in CSSR: Failure Counters-II
DNO Optimization Processes / JC Ejarque
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
Communicate the problem to Care department
CHECK alarm –BFD Alarm if exist
DMPG problem in RNC
RRC_CONN_STP_FAIL_TRANS Evaluate Number of reconfiguration failure due the transmission
Check COCO Configuration
Cross check PCR value & verify AAL2 Connection failure .
Expand the capacity or decrease the traffic offered to the site until the problem is solved For IP based Iub Check IP based route parameters Delete and Recreate the COCO : Reset the Site if sleeping cells alarm exist . Temporary decrease the Traffic or shift to GSM if the problem continuous exist with
High Failure
RRC_CONN_STP_FAIL_IUB_AAL2_TRANS
Updated when there is shortage or blocking of AAL2 resource
Cross check the PCR value & change as per Recommendation
Cross check the Transmission Alarms .
Reduce the Traffic or shift to GSM if the problem persist continuous with high failures .
18 © Nokia Siemens Networks DNO Optimization Processes / JC Ejarque
RRC Conn Setup & Access Analysis
If RRC setup/access failure due to Radio/MS, it is also possible to check whether UE s are located
at distance area or close to cell edge area
Propagate 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
PRACH_D
ELA
Y_C
LASS_0
PRACH_D
ELA
Y_C
LASS_1
PRACH_D
ELA
Y_C
LASS_2
PRACH_D
ELA
Y_C
LASS_3
PRACH_D
ELA
Y_C
LASS_4
PRACH_D
ELA
Y_C
LASS_5
PRACH_D
ELA
Y_C
LASS_6
PRACH_D
ELA
Y_C
LASS_7
PRACH_D
ELA
Y_C
LASS_8
PRACH_D
ELA
Y_C
LASS_9
PRACH_D
ELA
Y_C
LASS_1
0
PRACH_D
ELA
Y_C
LASS_1
1
PRACH_D
ELA
Y_C
LASS_1
2
PRACH_D
ELA
Y_C
LASS_1
3
PRACH_D
ELA
Y_C
LASS_1
4
PRACH_D
ELA
Y_C
LASS_1
5
PRACH_D
ELA
Y_C
LASS_1
6
PRACH_D
ELA
Y_C
LASS_1
7
PRACH_D
ELA
Y_C
LASS_1
8
PRACH_D
ELA
Y_C
LASS_1
9
PRACH_D
ELA
Y_C
LASS_2
0
0.00%
20.00%
40.00%
60.00%
80.00%
100.00%
120.00%
average
CDF
Low in CSSR: Additional counters
19 © Nokia Siemens Networks DNO Optimization Processes / JC Ejarque
Low in CSSR: Failure Counters
RAB setup & Access Fail Root Cause Analysis: RT and NRT (I/B) domains
RAB_STP_FAIL_XXX_AC
Check UL Interference, DL Power & Code occupancy if there is need to upgrade radio
capacity using the already distributed.
Check PrxTarget / PrxOffset / PrxMeasFilterCoeff – PtxTarget / PtxOffset /
PtxMeasFilterCoeff of the affected cells
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 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 until the problem is solved.
In case BTS is not responding delete and re-create COCO
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
Check COCO Configuration
check IUB Capacity
RAB_STP_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
Communicate the problem to Care department
20 © Nokia Siemens Networks DNO Optimization Processes / JC Ejarque
Low in CSSR: Failure Counters
RAB setup & Access Fail Root Cause Analysis: RT and NRT (I/B) domains
RAB_ACC_FAIL_XXX_UE
Evaluate Cell resource Prx and Ptx parameters (same as RAB_STP_FAIL_XXX_AC Case)
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
Communicate the problem to Care department.
21 © Nokia Siemens Networks
RRC CONN STP FAIL AC
DNO Optimization Processes / JC Ejarque
22 © Nokia Siemens Networks
RRC_CONN_STP_FAIL_BTS
DNO Optimization Processes / JC Ejarque
23 © Nokia Siemens Networks
RRC CONN STP FAIL _ TRANS
DNO Optimization Processes / JC Ejarque
24 © Nokia Siemens Networks
RRC CONN STP FAIL TRANS
DNO Optimization Processes / JC Ejarque
25 © Nokia Siemens Networks
RRC CONN STP FAIL _RNC
DNO Optimization Processes / JC Ejarque
BFD
ALARM
26 © Nokia Siemens Networks
RRC CONN STP FAIL FROZBS
DNO Optimization Processes / JC Ejarque
27 © Nokia Siemens Networks
FINAL IMP COUNTER
DNO Optimization Processes / JC Ejarque
28 © Nokia Siemens Networks
CRITICAL & MAJOR WCDMA ALARMS-I •
• Base Station generated alarms from HW problems:
• 61022 BFD down, 10.68.18.241
• 61605 BFD 1 down, ingress, 10.68.18.241 to 10.68.121.9
•
• 3117-- FAILURE IN SAAL UNI SIGNALLING LINK ACTIVATION
•
• 1.7650 BASE STATION FAULTY
• A critical fault has occurred in the Base Station. None the cells of this Base Station are capable of transmitting traffic and thus also HSDPA is unavailable in this Base Station.
• 2.7651 BASE STATION OPERATION DEGRADED
• A major fault (or faults) has occurred in the Base Station. Depending on the fault details this alarm may indicate problems with HSDPA (see also alarm 7776 below).
• 3.7653 CELL FAULTY
• Hardware fault in Base Station has an effect for a Cell. The Cell is unavailable for all traffic.
• 4.7654 CELL OPERATION DEGRADED
• Hardware fault in Base Station has an effect for a Cell. Depending on the fault details this alarm may indicate problems with HSDPA (see also alarm 7776 below).
• 5. 7772 PHYSICAL SHARED CHANNEL CONFIGURATION FAILED
• HSDPA channel configuration or reconfiguration to Base Station has failed. HSDPA is not available in given Cell.
•
•
DNO Optimization Processes / JC Ejarque
29 © Nokia Siemens Networks
CRITICAL & MAJOR WCDMA ALARMS-II
• 6. 7776 HSDPA FAILURE IN WCEL
• Base Station has informed RNC that it cannot provide HSDPA. The reason for the fault is either a hardware failure or a lack of capacity in Base Station. See Base Station generated alarms for fault details.
• . 7665 BASE STATION TRANSMISSION ALARM
• 10. 61058 Synchronization lost
• 11. 7650 BASE STATION FAULTY
• 12.7651 BASE STATION OPERATION DEGRADED
• . There is no limit to how many 7651 alarms can be active at the same time
• 13. 7652 BASE STATION NOTIFICATION
• . There is no limit to how many 7652 alarms can be active at the same time
• 14. 7653 CELL FAULTY
• . Start, the affected cell state is set disabled
• . Cancel, the affected cell state is set enabled
• 15. 7654 CELL OPERATION DEGRADED
• . There is no limit to how many 7654 alarms can be active at the same tim
•
• 19. 7661 BASE STATION LICENCE NOTIFICATION
• . Licence alarms do not have dependencies to other BTS alarms.
•
•
•
DNO Optimization Processes / JC Ejarque
30 © Nokia Siemens Networks
CRITICAL & MAJOR WCDMA ALARMS-III
DNO Optimization Processes / JC Ejarque
16. 7655 CELL NOTIFICATION
. There is no limit to how many 7655 alarms can be active at the same
time
17. 7665 BASE STATION TRANSMISSION ALARM
. In case of faulty transmission equipment or transmission software, this
alarm is
reported towards the OMS or NetAct.
. Transmission alarms do not have dependencies to other BTS alarms.
18. 7660 BASE STATION LICENCE EXPIRED
. Licence alarms do not have dependencies to other BTS alarms.
31 © Nokia Siemens Networks
Thank you
DNO Optimization Processes / JC Ejarque
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