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

[jenriqp]

Hi team,

I've been working with CHRs file and OMstar where I can see the fails percent by no.reply, the results are:

1.- There is a TIMSI with 15% of access failure. How to get this IMSI?
2.- 100% access fails cause "NoReply", there istn other causes. This apply for 3 sectors.

attach you can find the print out about the results. Please check it and hope for feedback

[sak2e]

Hi team,

I've been working with CHRs file and OMstar where I can see the fails percent by no.reply, the results are:

1.- There is a TIMSI with 15% of access failure. How to get this IMSI?
2.- 100% access fails cause "NoReply", there istn other causes. This apply for 3 sectors.

attach you can find the print out about the results. Please check it and hope for feedback

hi jenriq.

Could you inform me whats the meaning of TMSI FFFFFFF?
last time i tried also to find IMSI for UU no reply issue in my network. but i got no result :(

is you No reply message have an spesific hour? i mean the issue trigger in spesific hour

[smartyouth92]

It's seems that you've had a tough condition for cell reselection which it affect to serving cell through reducing coverage,so if the previous solution for other member not succeed so it's better to check layer-3 by performing a D.T then check the SIB information,After that you should change the parameter for reselection condition ,Hoping that it would solved

[marcengo]

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!

Reducing pilot to control overlap, you must be from LatAm :lol

[jenriqp]

Hi Yoyokdp,

FFFFFFF means rest of IMSIs because the omstar only shows top ten imsi or cells.

Second, the issues ocurrs suddenly anyhours.. it doesn't depend a specific hour and it occurs on three sectors.

[sak2e]

Hi Yoyokdp,

FFFFFFF means rest of IMSIs because the omstar only shows top ten imsi or cells.

Second, the issues ocurrs suddenly anyhours.. it doesn't depend a specific hour and it occurs on three sectors.

Great,, Your case is 100% same with mine and i still investigate without any further clue for this case :(

[jenriqp]

Hi guys,

I made a change on sector 3 (more affected) where i put QRxlevMin to -58 and RRC noreply numbers were decreased but im not sure if that change is the responsable (on 03/03/16) because there was a peak two days after that. in fact, sector has several days without fails, im thinking to put back the change to see the results. Attached you can find the pic about what i said. hopping yours comments

[sak2e]

Hi guys,

I made a change on sector 3 (more affected) where i put QRxlevMin to -58 and RRC noreply numbers were decreased but im not sure if that change is the responsable (on 03/03/16) because there was a peak two days after that. in fact, sector has several days without fails, im thinking to put back the change to see the results. Attached you can find the pic about what i said. hopping yours comments

Hi Jenriq,
what about other KPI such as RRC att and RRS Sr since you change to -58, probably the value is high enough for UE.
and thats qrxlevmin are for cellsel? cellresel? or what?

[jenriqp]

Hi yoyokdq,

This parameter is about cellresel, ue will strt to measurement UMTS when LTE signal is minor to -104. Means thats more restricted for to stay on LTE. Others KPI are good, users avg are a little low.

cheers

[sak2e]

Hi Jenrip,

great,, please inform us if the UU No Reply issue is decrease until end of your monitoring period, probably i will change that parameter as well

[Youssef]

Hi guys you can try to change some NO pusch POWER or rxlevmin