High RTWP on Cells

[ChristopherAlbertini]

Dear All,

Note that we are currently having almost 20 cells in the network with high RTWP (-68dm) affecting end users performances.
All the sites are deployed with NSN equipment.

Can any assist to troubleshoot this case?

Thanks
CA

[JCarlos21]

Dear ChristopherAlbertini (http://www.finetopix.com/member.php?30760-ChristopherAlbertini) ,

Does anyone has discarded the possibility of External Interference? When was the first time it started, is it a tendency or started all of the sudden?

Best regards,

[jskhalid]

Hi , i think is external , you shoud do some spectrum analyse to make sure.

BR

[samuraial]

-68dBm is caused from external(check the direction of the cells), or some sw trial probably from a RNC engineer, wrong background noise configuration comes to my mind.
Check rnc config if any changes occurred during the time of the rtwp problem.

B/R

[ChristopherAlbertini]

-68dBm is caused from external(check the direction of the cells), or some sw trial probably from a RNC engineer, wrong background noise configuration comes to my mind.
Check rnc config if any changes occurred during the time of the rtwp problem.

B/R

Thanks to All.

What should be a typical config to check from RNC?
Do you think that the feature HSUPA interference canceller can help?

[Rifa]

Did you try to do the PIM test on the affected sites using the PIM tester?
The tool should help you if there was anything wrong Antenna FL.
If you need to confirm external interference use the spectrum analyzer to check any interferer.

Regards

[samuraial]

Lat optlog and check the date when you had the abnormal RTWP.
-68dBm is high for IC to work IMO.
How much is the RTWP on night hours? Check at 02:00.

B/R



Thanks to All.

What should be a typical config to check from RNC?
Do you think that the feature HSUPA interference canceller can help?

[Naleen]

Dear CA,

This is probably an external interference. We are also having this kind of interference in some cells. In our case, interference sources are the unauthorized DECT 6.0 codeless phones operating in 1920 - 1930 MHz range (Affecting UL 9612 and 9617 UARFCN ranges). Can you tell me what is the UL frequency, using in your network?

BR,
Naleen.

[putrawhisnu]

if i may share technical step may useful :
1. analyze it whether it happen at busy hour only or every hour? if only at busy hour supposed to be normal
2. do you uses combiner for combining with 2G? if yes, try to disconnect the 2G / combiner and check -- maybe there is an issue of VSWR
3. There is parameter need to change if huawei called it as RSSI Unbalance Parameter, please evaluate the value
4. Yes, the last step is try to determnie is there any external interference -- you may increase / decrease power output :)

Good luck

[plannerguy]

HI

it would be good if u have spectrum analyzer . tune the equipment with the UL freq and perform DT in concerned area.

Rgds
Plannerguy

[fenixchoo]

Hi,

Maybe you should temporary disable the HSUPA 2ms tti before you can conclude in External or Internal interference.

[Ralphobafemi]

Hi.
For interference classification, consider the flow:
Internal Interference:
· The RTWP of main and diversity is usually irrelevant. If the RTWP is relevant, there must be special causes, such as the main and diversity are combined at some point.
· The interference is related to traffic. The interference occurs less probably when traffic is lower.
· The RTWP fluctuates sharply, as great as about 10 dB, or even greater than 10 dB.
· The interference will last for a period, without mutational change, which is different from that of external interference.
· In terms of time feature of RTWP, the RTWP changes irregularly.

External interference:
· The interference to main or diversity is relevant. Namely, in terms of time, the interference to main or diversity trends similarly, and the difference between them is within 5 dB.
· The external interference affects multiple cells that are geographically bordering.
· In terms of time feature of RTWP, the external interference is mutational, the interference occurs at a regular point and in a regular period, and lasts for a regular period (exceptions are microwave interference, improperly configured gain of repeaters, so the RTWP is not mutational).

I hope this helps.
RalphObafemi
#++ReputationPlease

[s.ahmedbensoultane]

http://www.finetopix.com/archive/index.php/t-17357.html

[bouhalloufa lotfi]

dear

have you MHA in your antena line device ?may be it is the problem ??because i have met of overload when we have used a MHA of E///,we need to apply a WA ?

BR

[fenixchoo]

Dear Lotfi,

Appreciate you can share the WA for good.
I think this RTWP issue is common these days.
Thank you

[Lamboy]

if high RTWP occur for whole cells, try to change system/RF module. beside, external interference might be another cause.


BR//