DL code congestion in E// W13

[jason182]

Hi,

I had congestion in DL code and I solved that by changing standaloneSrbSelector fro SRB136 to SRB34 or changing rateselection.dlPrefrate /ul from 64 to 16 .

But I don't know the impact on other KPIS, do you have any experience with these changes ?

Regards,

Jason

[electron]

Hi Jason,


By changing rateselection.dlPrefrate /ul as UE will be reserved by lesser UL CE for multi RABs then user scheduled Throughput will be lesser consequently but what ever it is it should be negligible or even you may not observe it at all then do not worry about this change.

Regarding standaloneSrbSelector as you changed SBR band width from 13.6 to 3.6 then your SBR will be maintained lesser than when it assigned to 13.6 there is probability of increasing Speech RAB drop rate let's keep monitor it .

Can you tell me how much was your admission code congestion counter per day for this cell. I may share more idea to improve your cell


Cheers
Hi,

I had congestion in DL code and I solved that by changing standaloneSrbSelector fro SRB136 to SRB34 or changing rateselection.dlPrefrate /ul from 64 to 16 .

But I don't know the impact on other KPIS, do you have any experience with these changes ?

Regards,

Jason

[babak1349]

Hi,

I had congestion in DL code and I solved that by changing standaloneSrbSelector fro SRB136 to SRB34 or changing rateselection.dlPrefrate /ul from 64 to 16 .

But I don't know the impact on other KPIS, do you have any experience with these changes ?

Regards,

Jason

Hi,
SRB34 is using SF256 and SRB136 is using SF128 So with SRB34 you are using less codes. If it solved DL code congestion it looks to me you have a lot of RRC attempts so you need to check what is the major RRC attempts' cause and try to reduce the reason
What would be the potential impact I assume there might be 3 impacts:
1) Call setup time increase due to lower bit rate on signaling (SRB is signaling Radio bearer) or other NAS procedure time like as PDP Context activation, LU and so on
2) CSSR might decrease (depending on formula you are using) due to higher RRC drop. It can be fixed by looking at maximum RL power and increasing the allowed RL low rate power. you have to check minPwr, maxpwr, min rate ...... parameter set
3) check RRC drop rate as well

cheers

[jason182]

@ Électron
I have 100 rrcdeniedadmdlchnlcode per day .

[electron]

change dlcodeadm for teh cell to 95% !
@ Électron
I have 100 rrcdeniedadmdlchnlcode per day .

[jason182]

I already changed it from 90 to 95 !
maxnumhspdschcodds 15/15/15/15

[electron]

for further action you may decrease admission for sf4 or sf8

Cheers
I already changed it from 90 to 95 !
maxnumhspdschcodds 15/15/15/15

[jason182]

I'm not fun to decrease sf8adm but I will try it ;)

[babak1349]

change dlcodeadm for teh cell to 95% !

Hello,
You need to check how many RRC attempts you have and then check the ratio between RRC admission rejection and RRC attempts
I suggested to check cause of RRC attempts, for example RRC request for LU, call originating, call terminating,,, registration and so on
I guess probably you have high RRC attempts on LAC boarder or maybe you have high coverage area for the specific cell or maybe you have huge overlapping with neighboring cell

furthermore you can check static HSDPA channel allocation numHsPdschCodes you can reduce it if it is really high

cheers