High RTWP when we activate Second carrier [Archive]

View Full Version : High RTWP when we activate Second carrier

sadok

2011-02-08, 01:07 PM

Hi,

We are facing problem when 2 carrier is activated the RTWP ramp to -50 dbm

is there who have idea about this problem?

regards

sala70vic

2011-02-08, 05:45 PM

Hi,

We faced same issue with Huawei in some NodeBs, please refer to the attached problem report.
regards,

Sala70vic
--------------------
Please Add rep and thanks if you see it is useful

sadok

2011-02-08, 06:02 PM

Thank you for sharing this documents, it is really helphul from u.

But in my case this problem happen on Indoor site which are using Distributed Antenna System. And the Rtwp is higly increased up to -50 dB.

I m suspecting that the cause is due to DAS syetem but I do not know how to prove it.

wolverine

2011-02-08, 09:39 PM

Lock the first carrier cells and see if the RTWP improves. Then unlock them and see if it deteriorates again. If so, you have proven that something is not right with the cabling. Are you using the same PAs for both carriers under the same sector?

sadok

2011-02-10, 11:56 AM

Yes we are using same PA 40 w, investigation is going on, I m thnking that the propleme could be the cabling or the combiners.

I will update you by our findings .

patek1968

2011-02-10, 12:02 PM

Check the components first..possibly there's something loose or not properly sealed..

hari_2208

2011-02-10, 01:30 PM

looks more like some hardware malfuntion @ radio of IBS

redtomato168

2011-04-06, 10:19 PM

riyantoyadi

2011-04-06, 11:03 PM

i already got experience in many indoor places, most probably :

1. Multiband Combiner problem (not support 2nd carrier)

2. Leak Antenna (DAS) from connector, please re-checking every single DAS

Hopefully its clear yah

soodlhor

2011-04-09, 02:26 AM

just problem from your passive unit having high reflex power, maybe caused by too low isolation, try to reduce CPICH power -3 on each carrier for testing.

Philippe

2011-07-18, 12:23 PM

Hi,

We faced same issue with Huawei in some NodeBs, please refer to the attached problem report.
regards,

Sala70vic
--------------------
Please Add rep and thanks if you see it is useful

I cannot yet read the attached report so excuse me if the answer is in the document. I'm interested in knowing if any similar problem occured with Huawei UMTS 850 RRU product for macro deployment (not DAS indoor deployment)? And if there was new release of RRU or NodeB product to solve this known problem, unless the problem was coming from PIM in the feeder/antenna installation?

Philippe

2011-08-04, 07:50 PM

Hi,

We faced same issue with Huawei in some NodeBs, please refer to the attached problem report.
regards,

Sala70vic
--------------------
Please Add rep and thanks if you see it is useful

Thanks for the report. I still do not understand the Huawei answer. Did they give any additional clarification?
Did you finally swap all the 40W RRU?
I'm currently facing higher RTWP degradation than the 1 to 2dB you faced. In particular when the site is transmitting at full power. Did you notice a greater RTWP degradation when the RRU is transmitting at maximum power (e.g. due to HSDPA traffic)?

revolution

2011-08-04, 10:55 PM

HI

U need to isolate the problem step by step

First check the parameters and the setting for feeder loss and attenuation .
Second U can add dummy load at the output port of the BTS and check what is the RTWP .
Then move this load step by step after each connection and then u can find the fault