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21st November 2011 at 07:53 #67531Man UGuest
I have some cells suffer from bad UL as compare with DL level your support Plz ,
Vendor is huawei21st November 2011 at 09:18 #67532pixGuest
can you check their path balance ?
pix23rd November 2011 at 11:42 #67533Man UGuest
Hi Pix I already checked PB &TA both of them are OK23rd November 2011 at 22:06 #67534pixGuest
what ul rxlev and dl rxlev do you observe ?
how do you measure those values ?
how many trx in this cell ?
pix28th November 2011 at 06:57 #67535Man UGuest
Hi Pix The difference reach to 20dB for some cells ,
6 TRXs &4TRXs28th November 2011 at 16:08 #67536pixGuest
so you mean RXLEV_UL = -90dBm and RXLEV_DL = -70dBm ?
here is a simplified link budget, for a cell with 6 TRX:
trx tx = 46dBm
2 * combiners = -9dB
feeder/antenna/radio loss = -100dB (as an example.)
–> RXLEV_DL = -63dBm
ms tx = 33dBm
feeder/antenna/radio loss = -100dB
ul diversity gain = +3dB
–> RLEV_UL = -64dBm
So for such cell, the UL and DL should be similar (assuming your trx-tx-power are around 46dBm).
Since you are seeing a big difference it’s either:
-bad path balance on at least one trx
– power control in UL but no in DL -> either you didn’t activate it , or there is a bad quality in DL therefore the TRX has to transmit stronger.
pix29th November 2011 at 08:27 #67537Man UGuest
many thanks for your answer
Just small note
DL&UL PC =YES FOR ALL BSC30th November 2011 at 10:54 #67538pixGuest
so you think the difference you saw was caused by power control ?30th November 2011 at 11:21 #67539Man UGuest
No , pix cuz both of them are Activate UL\DL30th November 2011 at 14:26 #67540pixGuest
yes, they can be activated but they will not attenuate the signal symmetrically. If there is a bad RXQUAL in DL? then the DL signal is less reduced than the UL.
I’m quite certain that what you are seeing is due to PC.
Otherwise you should see an unbalanced Path_Balance in the TRX. Since you don’t see it… it has to be PC.