After Rehoming from old RNC to new one CS & PS Drop increase (SRB Reset-UuNoReply)

[aleon23]

Hi everyones,

After rehoming 35 nodesb from old RNC to new RNC, one nodeB has problems related to drop call ratio(amr & data), the causes are SRB Reset and UuNoReply but coverage parameters are the same as before rehoming, we checked all parameters in mml no difference too.Also KPI for transition HSDPA to FACH decrease in the same time.

Please your help to improve these KPIs.

Any idea is welcome..

Thanks in advance""

[hoangnamhut]

You should check neighbor parameter of NodeB. Maybe missing neighbor cause drop call rate increase.

[D33T0X]

Check neighbour definitions and parameters - check that the external cells are properly configured - I think your problem is there. I'm doing the same rehoming exercise but have a very deep consistency check after rehoming. I always find configuration problems - after correction all goes well.

Good luck

Hi everyones,

After rehoming 35 nodesb from old RNC to new RNC, one nodeB has problems related to drop call ratio(amr & data), the causes are SRB Reset and UuNoReply but coverage parameters are the same as before rehoming, we checked all parameters in mml no difference too.Also KPI for transition HSDPA to FACH decrease in the same time.

Please your help to improve these KPIs.

Any idea is welcome..

Thanks in advance""

[Budaxbaix]

Hi, may be this document will help. Check FACH & RL power
AMR Power configuration Causes CS Call Drop Rising During Swapping.zip

[aleon23]

Hi Nudaxbaix,

Do you know which command is for check this actual configuration? Because from mml file only can find MAXFACHPOWER=10 from UFACH command..

Thanks,

[YANG SONG]

Hi everyones,

After rehoming 35 nodesb from old RNC to new RNC, one nodeB has problems related to drop call ratio(amr & data), the causes are SRB Reset and UuNoReply but coverage parameters are the same as before rehoming, we checked all parameters in mml no difference too.Also KPI for transition HSDPA to FACH decrease in the same time.

Please your help to improve these KPIs.

Any idea is welcome..

Thanks in advance""

Create data again like a new site. there must something wrong with it,only to check all parameters maybe not find the Invisible wrong,

first you must make sure the Equipment hardware working normal,

hope to help u

[Budaxbaix]

Hi Nudaxbaix,

Do you know which command is for check this actual configuration? Because from mml file only can find MAXFACHPOWER=10 from UFACH command..

Thanks,

The value is relative to CPICH, if CPICH 33 dbm so
FACH = 33 + 10*0.1 (actual step) = 34 dBm

the Parameter CELLRLPWR
for AMR :
CNDOMAINID CS_DOMAIN
MAXBITRATE 12200
RLMAXDLPWR 0
RLMINDLPWR -150
DLSF D128

Maximum AMR DCH DL power = 33 + 0 = 33 dBm

We can increase max & min RL Power t reduce call drop in TopN Cell
i.e
RLMAXDLPWR 10
RLMINDLPWR -140

[aleon23]

Check neighbour definitions and parameters - check that the external cells are properly configured - I think your problem is there. I'm doing the same rehoming exercise but have a very deep consistency check after rehoming. I always find configuration problems - after correction all goes well.

Good luck

Hi D33T0X,

I checked neighbour definitions, everything fine (neighbors in both directions, NRNCCell because this nodeB is edge between RNCs, new LAC-RAC-URA). Also I checked CHRs and the common reason is "RrcErrorCause: RR_ERR_RNCAP_RLC_FAILURE_SRB_RST", for CS and PS services, but for coverage no physical change was performance after rehoming, so it's strange have this Error Cause related to coverage.

Any suggestions to check parameters, which logic parameters are important to review?

Thanks advance,

[aleon23]

The value is relative to CPICH, if CPICH 33 dbm so
FACH = 33 + 10*0.1 (actual step) = 34 dBm

the Parameter CELLRLPWR
for AMR :
CNDOMAINID CS_DOMAIN
MAXBITRATE 12200
RLMAXDLPWR 0
RLMINDLPWR -150
DLSF D128

Maximum AMR DCH DL power = 33 + 0 = 33 dBm

We can increase max & min RL Power t reduce call drop in TopN Cell
i.e
RLMAXDLPWR 10
RLMINDLPWR -140

Dear Budaxbaix,

So if change it

RLMAXDLPWR 10
RLMINDLPWR -140

Maximum AMR DCH DL power would be = 33 + 10 = 43 dBm

Or what is the steps for RLMAXDLPWR 10, because documentations detailed: RL Max DL TX power
Meaning: This parameter should fulfill the coverage requirement of the network planning, and the value is relative to [PCPICH transmit power]. If the parameter is excessively high, downlink interference may occur. If the parameter is excessively low, the downlink power control may be affected. For detailed information of this parameter, refer to 3GPP TS 25.433.
GUI Value Range: -350~150
Actual Value Range: -35~15, step:0.1
Unit: dB
Default Value: None
Recommended Value: None


thanks in advance,

[Budaxbaix]

Hi,

So if change it

RLMAXDLPWR 10
RLMINDLPWR -140

Maximum AMR DCH DL power would be = 33 + 10 = 43 dBm

10 mean 1 (10*0.1 step size)

Maximum AMR DCH DL power would be = 33 + 1 = 34 dBm