Call drop rate in 3G WCDMA is important thing to optimize in our Network. There are many ways to improve drop call such as hardware problem detection, Fix Coverage overlapping, Fix Missing neighbor and Parameter changing. You can refer to previous chapter about Drop Call Rate Improvement to know step by step about call drop reasons and optimization. What I want to share now is about how to improve drop call rate in 3G UMTS/WCDMA by Parameter adjustment. Before go to the topic we need to know call drop reasons in 3G UMTS:
- High Interference : As we know in that 3G UMTS/WCDMA is self interference because only use 1 frequency and differentiated by Scrambling Code(SC).
- Pilot pollution :Happened due to Coverage overlapping.You need to make sure first no coverage overlapping and can be solved by Physical optimization(Antenna down tilt).
- Missing Neighbor: Make sure no missing neighbor in your network to improve drop call before you start with Parameter optimization.
- Hardware problem: You need to fix first if you found hardware issue.
After you clear main issue for above reasons then you can go to Parameter optimization to reduce drop call rate. Here are recommended Parameter to reduce call drop rate in 3G UMTS/WCDMA for Huawei Network. If you work for other Vendor you can refer to your document and looking for same Parameter.
1. Increase HOASUTMR
1. Increase HOASUTMR
HOASUTMR meaning HO active set update response timer, A timer to RNC wait for the response to active set update in soft handover procedure. You can improve call drop in 3G by increase this parameter.
2. Increase Parameter 2D/2F
The idea of this parameter setting is to make fast Handover to GSM network. You can increase 2D/2F parameter and improve your drop call in 3G by moving traffic to GSM network.
Detail parameter need to be changed are as follow:
- INTERRATCSTHD2DECN0, ex: Change from -14 to -12
Detail parameter need to be changed are as follow:
- INTERRATCSTHD2DECN0, ex: Change from -14 to -12
- INTERRATCSTHD2FECN0, ex: Change from -12 to -10
- INTERRATCSTHD2DRSCP, ex: Change from -100 to -98
- INTERRATCSTHD2FRSCP, ex: Change from -97 to -95
- INTERRATHTHD2DECN0, ex: Change from -15 to -12
- INTERRATR99PSTHD2DECN0, ex: Change from -15 to -13
- INTERRATHTHD2FECN0, ex: Change from -13 to -10
- INTERRATR99PSTHD2FECN0, ex: Change from -13 to -10
- INTERRATHTHD2DRSCP, ex: Change from -100 to -95
- INTERRATR99PSTHD2DRSCP, ex: Change from -100 to -95
- INTERRATHTHD2FRSCP, ex: Change from -107 to -105
- INTERRATR99PSTHD2FRSCP, ex: Change from -107 to -105
- INTERRATCSTHD2DECN0:
Threshold to trigger inter-RAT measurement with measurement quantity of Ec/No for CS domain services
Value range: -24~0
Physical unit: dB
Content: For CS domain services, when Ec/No is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to activate compressed mode and start inter-RAT measurement, if the UE reports the event 2D when the measured value is smaller than the value of this parameter.
Recommended value (default value): -14
- INTERRATCSTHD2FECN0
Threshold to stop inter-RAT measurement with measurement quantity of Ec/No for CS domain services
Value range: -24~0
Physical unit: dB
Content: For CS domain services, when Ec/No is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to deactivate compressed mode and stop inter-RAT measurement, if the UE reports the event 2F when the measured value is larger than the value of this parameter.
Recommended value (default value): -12
- INTERRATCSTHD2DRSCP
Threshold to trigger inter-RAT measurement with measurement quantity of RSCP for CS domain services
Value range: -115~-25
Physical unit: dBm
Content: For CS domain services, when RSCP is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to activate compressed mode and start inter-RAT measurement, if the UE reports the event 2D when the measured value is smaller than the value of this parameter.
Recommended value (default value): -100
- INTERRATCSTHD2FRSCP
Threshold to stop inter-RAT measurement with measurement quantity of RSCP for CS domain services
Value range: -115~-25
Physical unit: dBm
Content: For CS domain services, when RSCP is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to deactivate compressed mode and stop inter-RAT measurement, if the UE reports the event 2F when the measured value is larger than the value of this parameter.
Recommended value (default value): -97
- INTERRATHTHD2DECN0
Threshold to trigger inter-RAT measurement with measurement quantity of Ec/No for PS domain HSPA services
Value range: -24~0
Physical unit: dB
Content: For PS domain HSPA services, when Ec/No is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to activate compressed mode and start inter-RAT measurement, if the UE reports the event 2D when the measured value is smaller than the value of this parameter.
Recommended value (default value): -15
- INTERRATR99PSTHD2DECN0
Threshold to trigger inter-RAT measurement with measurement quantity of Ec/No for PS domain R99 services
Value range: -24~0
Physical unit: dB
Content: For PS domain R99 services, when Ec/No is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to activate compressed mode and start inter-RAT measurement, if the UE reports the event 2D when the measured value is smaller than the value of this parameter.
Recommended value (default value): -15
- INTERRATHTHD2FECN0
Threshold to stop inter-RAT measurement with measurement quantity of Ec/No for PS domain HSPA services
Value range: -24~0
Physical unit: dB
Content: For PS domain HSPA services, when Ec/No is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to deactivate compressed mode and stop inter-RAT measurement, if the UE reports the event 2F when the measured value is larger than the value of this parameter.
Recommended value (default value): -13
- INTERRATR99PSTHD2FECN0
Threshold to stop inter-RAT measurement with measurement quantity of Ec/No for PS domain R99 services
Value range: -24~0
Physical unit: dB
Content: For PS domain R99 services, when Ec/No is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to deactivate compressed mode and stop inter-RAT measurement, if the UE reports the event 2F when the measured value is larger than the value of this parameter.
Recommended value (default value): -13
- INTERRATHTHD2DRSCP
Threshold to trigger inter-RAT measurement with measurement quantity of RSCP for PS domain HSPA services
Value range: -115~-25
Physical unit: dBm
Content: For PS domain HSPA services, when RSCP is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to activate compressed mode and start inter-RAT measurement, if the UE reports the event 2D when the measured value is smaller than the value of this parameter.
Recommended value (default value): -110
- INTERRATR99PSTHD2DRSCP
Threshold to trigger inter-RAT measurement with measurement quantity of RSCP for PS domain R99 services
Value range: -115~-25
Physical unit: dBm
Content: For PS domain R99 services, when RSCP is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to activate compressed mode and start inter-RAT measurement, if the UE reports the event 2D when the measured value is smaller than the value of this parameter.
Recommended value (default value): -110
- INTERRATHTHD2FRSCP
Threshold to stop inter-RAT measurement with measurement quantity of RSCP for PS domain HSPA services
Value range: -115~-25
Physical unit: dBm
Content: For PS domain HSPA services, when RSCP is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to deactivate compressed mode and stop inter-RAT measurement, if the UE reports the event 2F when the measured value is larger than the value of this parameter.
Recommended value (default value): -107
- INTERRATR99PSTHD2FRSCP
Threshold to stop inter-RAT measurement with measurement quantity of RSCP for PS domain R99 services
Value range: -115~-25
Physical unit: dBm
Content: For PS domain R99 services, when RSCP is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to deactivate compressed mode and stop inter-RAT measurement, if the UE reports the event 2F when the measured value is larger than the value of this parameter.
Recommended value (default value): -107
Thanks for reading Call Drop Rate improvement by Parameter change in 3G UMTS/WCDMA Huawei, hope can help you best network.
You might also Need to know:
Any other solutions for the CDR enhancement with changing parameters or switchs
ReplyDeleteActivate RB Release RL & RB Setup Enhanced Reestablishment
DeleteSET URRCTRLSWITCH:PROCESSSWITCH4=RRC_CONN_SETUP_OPT_SWITCH-1&RB_REL_RL_REEST_SWITCH-1&RB_SETUP_ENHANCE_RL_REEST_SWITCH-1;
Hey man.
ReplyDeleteI´m not sure if It is mandatory to change all thresholds you showed to move traffic faster to GSM, Could you explain what happend if I just Change the first five?
they basically change irat for all 3 services dch, r99 and hsdpa
Deletemind you to check if you need to change all 3 or not... depends on your kpi requirements
let's try men :). all threshold should be changed to get big impact
ReplyDeleteA debt of gratitude is in order For sharing this Superb article.I utilize this Article to demonstrate my task in college.it is helpful For me Great Work. camping generators
ReplyDeleteINTERRATHTHD2DRSCP is "start" value so it has to be lower than stop value INTERRATHTHD2FRSCP
ReplyDeleteyou have inverted those values.
anyway it´s a good suggestion to increase irat handover