DL signal strength low on just BCCH TRx

[zaebolll]

Hello guyz,
I have a specific problem that never seen before, need your help on that issue.

I have a cell which have 6 TRx. And my main problem is that average dl signal strength is too low(-107db) on BCCH Trx.

* When I swap signalling channels on other TRx, this time that new BCCH TRx degrades.

* When I lock BCCH Trx, new BCCH assigned TRx degrades.

When i check signal stregth of per TRx, always only BCCH TRx has low DL signal strenth, other hopping TRx's are working normal. When i swap BCCH on that normal working hopping TRx, that time i have same problem on that NEW BCCH TRx and on the other hand OLD BCCH TRx improves.

Hope i explained my problem well.
NSN systems
There is no any alarm
Problem started 5-6 days ago, and SD drops are increased.
Thanks in advance.

[zaebolll]

No idea guyz? :confused:

[fon909]

Did you have the site verified physically? Did you check losses? check feeder connections, jumper cable connections..Check the BCCH - BSIC plan thoroughly..

[pushp1986]

Check BCCH-BSIC plan.
Change the trx Prioty.
And You can shift the SD to another TRX that will help u decrease in SD drop.:)

[Alphonso]

I would like to know if this problem is happeing to the other cells of the same site.From wat you explained the problem is not hardware related.Ensure the CGI for the cell in question is the same configured in the Switch.

[_lisi4king]

I don't know about NSN, but can you check power tuning for all TRX's on this cell. I only try to guess, but as example BCCH has lower power settings than TCH's and when you lock BCCH TRX and BCCH jump to another TRX - > settings follow to BCCH. Sounds strange, i understand, but need to check all what possible ;)

[electron]

Hello guyz,
I have a specific problem that never seen before, need your help on that issue.

I have a cell which have 6 TRx. And my main problem is that average dl signal strength is too low(-107db) on BCCH Trx.

* When I swap signalling channels on other TRx, this time that new BCCH TRx degrades.

* When I lock BCCH Trx, new BCCH assigned TRx degrades.

When i check signal stregth of per TRx, always only BCCH TRx has low DL signal strenth, other hopping TRx's are working normal. When i swap BCCH on that normal working hopping TRx, that time i have same problem on that NEW BCCH TRx and on the other hand OLD BCCH TRx improves.

Hope i explained my problem well.
NSN systems
There is no any alarm
Problem started 5-6 days ago, and SD drops are increased.
Thanks in advance.


This problem is usual in E******* systems 100% the dTRU (1 unit which contains 2 TRX) is faulty in this case block both of them and observe most probably problem will be disappeared

[kevin_h811]

Hi zaebolll,

Have you tried to Soft Reset and Hard Reset the site or Delete-Recreate the parameters at the BSC?
We had this kind of situation or issues before.

BR//

[gprastomo]

Did you check the TRX till antenna cabling ? may be it has cross on the cabling, either TRX to combiner or combiner to antenna.

6 TRX, if you have 4 to 2 combiner, i guess you need 2 antenna and 2 combiner, so need to be carefull about the installation.