Bad Rxqual issues

[bdplanner]

Hello experts,
I am working on a swap project . installing new huawei 6900 bsc. We are having tough time with quality issue. During DT we are finding samples with very good rxlevel with very bad rxqual samples. is there any solution that you can suggest? all the sites with multiband with rf hopping . one dt log is uploaded for ur suggestion

Thanks

[tremalnike]

The problem is in bad SFH freq planning in cell 36385, bad MAIO and HSN planning also.
http://www.finetopix.com/picture.php?albumid=21&pictureid=90

Cell 36835 hoping channels 90,92 are adjacent to Cell 36836 BCCH frequency channel 91 and cause interference by adjacency channel. Signaling is bad and result is call drop. Cell 36836 Inner zone is in DCS band and it isn't affected - this explain good C/I we have there .

36836 also interfere with himself: BCCH is 105 ARFCN, in hopping list we have 104 and 106 ARFCN.

Cells has same MAIO and HSN !!

Take look in --> signaling --> error reports - it will explain everything - a lots of "Undecoded SACCH Message" .

Greetings !

[bdplanner]

The problem is in bad SFH freq planning in cell 36385, bad MAIO and HSN planning also.
http://www.finetopix.com/picture.php?albumid=21&pictureid=90

Cell 36835 hoping channels 90,92 are adjacent to Cell 36836 BCCH frequency channel 91 and cause interference by adjacency channel. Signaling is bad and result is call drop. Cell 36836 Inner zone is in DCS band and it isn't affected - this explain good C/I we have there .

36836 also interfere with himself: BCCH is 105 ARFCN, in hopping list we have 104 and 106 ARFCN.

Cells has same MAIO and HSN !!

Take look in --> signaling --> error reports - it will explain everything - a lots of "Undecoded SACCH Message" .

Greetings !
Thanks mate. Actually before swap this network was with E******* BSC with above config and the mpd was good too . But now they have swapped them with Huawei which is causing this rxqual issue. can you please let me know without changing the frequency plan , is there any other alternatives? The same cell bcch has adjc frequencies in its TCH MALIST . This config is actually same for all the network. Please find another log with same RXqual issue


Thanks for your valuable time.

[tremalnike]

Actualy, the second logfile has same problem by me.
http://www.finetopix.com/picture.php?albumid=21&pictureid=91
Uplink interference is visible too, by seeing high MS_TxPower in places with perfect RxLevel.

I'm not sure that config before swap is the same. Could you share log files (at same or near locations) before swap ? It is quite interesting.

The right approach when implement SFH is to separate channels like this:

BCCH's: 90,91,92,93,94,95,96,97
TCH's:98,99,100,101,102,103,104,105,106 and etc.
Cells at same site and neighbor cells needs to have minimum ServingCellBCCH+2 ARFCN.


One more question - Why you don't use Ciphering ?

Best Regards !

[loihut]

Actualy, the second logfile has same problem by me.
http://www.finetopix.com/picture.php?albumid=21&pictureid=91
Uplink interference is visible too, by seeing high MS_TxPower in places with perfect RxLevel.

I'm not sure that config before swap is the same. Could you share log files (at same or near locations) before swap ? It is quite interesting.

The right approach when implement SFH is to separate channels like this:

BCCH's: 90,91,92,93,94,95,96,97
TCH's:98,99,100,101,102,103,104,105,106 and etc.
Cells at same site and neighbor cells needs to have minimum ServingCellBCCH+2 ARFCN.


One more question - Why you don't use Ciphering ?

Best Regards !

Very good! Many thanks!