Decrease Power - Reference Signal (LTE - Huawei)

[jenriqp]

Dear experts,


I've read that it doesnt recommended power descrease in RS when I need to limit coverage, but I have several sites with systems RET faulty.
My question is what should I do if I need to limit coverage releated to the power?




thanks in advanced

[sak2e]

It will be ok if you reduce RS Power as long as you monitor the timing advance after CR applied.

[jenriqp]

thanks Yoyokdp,

I'm going to change RS from 18.2 to 16.2 dBm. monitoring load users and coverage based on TA. I've had a lot of cells with RRC fails noReplay and I always try to reduce coverage with DTilt . Do you know another way to avoid these fails noreplay?

[sak2e]

Hi,

As i know RRC fails no Replay happened because UE didn't send RRC setup complete message to EnodeB. I am agreed with you, you can try as follow:
1. Do some downtilt to make sure there are no overshooting coverage. Its better to downtilt instead of reduce Rs Power. i just afraid the penetration will be low to the UE
2. Do some CHR trace to find out the percentage of RRC fails no replay in a EnodeB
3. Is there any UL Interference?

[jenriqp]

hi Yoyokdp,


1. Do some downtilt to make sure there are no overshooting coverage. Its better to downtilt instead of reduce Rs Power. i just afraid the penetration will be low to the UE
you right about to do DTilt instead of reduce PW RS, but I have some sites with RET Faulty systems and customer wants another method.


2. Do some CHR trace to find out the percentage of RRC fails no replay in a EnodeB.
I havent done CHR trace but I have statistics where it shows an amount of RRC fails no replay that degrade to the Accessibility KPI
3. Is there any UL Interference?
I checked PUCCH/PUSCH interefence and I didnt find isuess.

[babak1349]

hi Yoyokdp,


1. Do some downtilt to make sure there are no overshooting coverage. Its better to downtilt instead of reduce Rs Power. i just afraid the penetration will be low to the UE
you right about to do DTilt instead of reduce PW RS, but I have some sites with RET Faulty systems and customer wants another method.


2. Do some CHR trace to find out the percentage of RRC fails no replay in a EnodeB.
I havent done CHR trace but I have statistics where it shows an amount of RRC fails no replay that degrade to the Accessibility KPI
3. Is there any UL Interference?
I checked PUCCH/PUSCH interefence and I didnt find isuess.

hello
before RRC setup procedure , there is PRACH, so users already passed it means system could decode the request from users, besides there was resource allocation for RRC connection but user didn't sent the RRC connection Setup complete or enodeB couldn't decode it
So user might moved out of LTE coverage or really bad radio condition was happening in UL
you might check the parameters of IRAT re-selection and it might be tuned properly

Cheers

[marcengo]

I`m always against reducing the pilot, either in LTE or UMTS. You end up masking issues of performance/capacity while also in the very least ruining the Ec/No or RSRQP of your network, among other issues.

[jenriqp]

Hi Babak1349!


I agree with you before RRC procedure, but PRACH statistics are ok. I regarding to RF condition if cell is foraneus so I always check TA and apply downtilt while requiere it. But I've had some cases where cells are in dense area and their coverage is at least 300m., so I take as option checking UL intereference, intermodulation from antenna port etc.


Im going to check reselection parameter and i'll give you feeeback.

[jenriqp]

Hi marcengo,


Im againts to reduce pilot too, but some clients want to reduce operative costs applying methods like reducing pilot to avoid overlapping.

cheers!

[sak2e]

Hi Jenriq,

in the NO reply issue happened on spesific hour?
if yes, please do CHR collecting data to make sure the root cause